Britney Spears, who also has a house in her home state, flew in from California to be there and shared a picture of Maddie on Instagram, writing, "Need all the wishes and prayers for my niece."
We can't even begin to imagine how the family is coping, but we know that the Spears sisters, though usually separated by a few thousand miles, have maintained a closeness over the years, that sisterly bond always there for them even when day-to-day life gets in the way.
Just a week ago, Jamie Lynn posted a meme reading, "Im so bad at keeping in touch w ppl if we don't talk anymore just know I love u I just suck at communicating like a regular person."
That can easily extend to best friends, siblings, parents...even more so if you're a busy parent too, as Jamie Lynn and Britney are. At the same time, that fosters yet another kind of closeness, because Jamie Lynn has her two nephews, Sean Preston and Jayden James, to dote on, and Britney has had the same with Maddie.
Talking about the birth of her niece back in 2008, Britney told OK!, "That was special, but it was also strange because she's always been the baby, and now the baby was having a baby. It was mind-boggling. I was shocked a little bit. But it was really cool, and she was happy. When she got to the hospital, we all thought it was going to be an all-day thing, and instead, the baby just sort of popped out. 'OK, we're happy now!'"
Jamie Lynn, who had been starring in Nickelodeon's Zoey 101, made a lot of headlines when she got pregnant at 16, but her family maintained a seamless show of support throughout her unexpected journey.
"She's going to come out here for the kids' birthdays. It will be the first time the cousins meet," Britney continued in the above interview. "I'm sure the boys will be like big brothers to Maddie."
"For now, Maddie's biggest concern in life is when she gets to see her cousins next," Jamie Lynn told Glamour in 2012 when Maddie was about 3 1/2. "She's always asking, 'Why can't we have Preston and JJ here?' They're very close. They're like brothers and sister. They're so stinking cute.
"And Maddie loves her Aunt Britney's songs. She just loves the whole dress-up thing that goes with it. She loves dancing and singing and all of that. I definitely think music is in her genes."
A photo posted by Jamie Lynn Spears (@jamielynnspears) on
Jamie Lynn has also talked about learning from how the press treated Britney during her toughest times (and during her regular, everyday times) that that sort of scrutiny was something she did not want for her young family.
She moved to Mississippi and was initially engaged to Maddie's father, Casey Aldridge, but they broke up for good in 2010. Jamie Lynn married businessman Jamie Watson—they call themselves Jamie Squared—in 2014.
Talking about her decision to stay far away from Los Angeles, she told Entertainment Tonight last summer, "I knew my story was going to be something people wanted to know about, of course, tabloid gold... The hardest part for me was trying to figure out why these grown men were following this young girl around who is already going through so much in the middle of nowhere. I was so scared already, I didn't want that added pressure."
Jamie Lynn and Maddie moved to Nashville in 2009 when the former child star decided she was ready to resume her music career.
"Obviously seeing [the coverage of Britney], I knew how far it could go," Jamie Lynn told Glamour. "I've never wanted to be put under that kind of scrutiny. I just wanted to get away from it as much as I could, to just go away and be a mom and figure out what I wanted, and to earn a sense of respect back for myself. Move to a town in the middle of nowhere and just raise my child. All I could be was a good mother. If anybody had anything to say after that, there was nothing I could do."
Now that they're both adults, Jamie Lynn and Britney can have a laugh over the more random headlines out there—such as when John Stamostold Billboardlast year that Britney had once tried to set his Scream Queens costar Taylor Lautnerup with her little sis.
"We did not go out," Lautner added.
Jamie Lynn posted some of the article pickup, writing, "Haha I never heard anything about this, until my dad sent me the story…My sister looks out for me, even when I don't know it She's da best."
Britney has always kept a close watch on Jamie Lynn, even from afar. Back when her kid sister was really still a kid, Brit said in an interview, "I love my little sister, and I am overprotective with her. I don't mind saying that." She added, fondly, "My sister is a handful. We are so different. Actually she would be a lot better in this business than I am. Her personality, she is Miss Diva. She is so full of herself, it's so cute."
MTV Films/Zomba Films
"'Aw, Britney Spears' sister,'" a barely 11-year-old Jamie Lynn mimicked the usual reaction people had to her. "Tryin' to change it to Jamie Lynn Spears, you know. And so that's why I'm gonna try to go be taken as a serious actress before I ever move on to doing serious singing." She was a featured player on Nickelodeon's All That at the time (Britney made a few appearances over the years) and in 2005 she landed her starring role on Zoey 101.
And while circumstances probably got in the way of the sisters working together more, no one can forget Jamie Lynn playing the younger version of Britney's character in the cult-classic Crossroads, and years later she collaborated on the Britney Jean track "Chillin' With You."
As their kids have gotten a little older, they've seemingly been carving out more time to be together, aside from the usual holiday visits.
Britney and their brother, BryanSpears, introduced Jamie Lynn when she performed at the Grand Ole Opry last March, and big sis got a little emotional while doing so.
"Thanks to the Opry for letting me introduce this beautiful, young lady who is my heart and my soul," Britney, making a surprise appearance, said. "Not only is she beautiful and extremely talented, she's my little sister...Jamie Lynn Spears!"
A teary-eyed Jamie Lynn walked onstage and the two shared a big hug.
"I can't believe it, my whole family kept this secret from me!" the "How Could I Want More" singer exclaimed.
Similarly, Jamie Lynn, her husband, Maddie and family matriarch Lynne Spears were in the house at the 2016 Billboard Music Awards that May when Britney was honored with the Millennium Award and tore through a medley of her hits in a performance that floored her fans.
"Truthfully, we were just there to celebrate, and it was awesome, and she looked so hot!" Jamie Lynne gushed on the CMT Music Awards red carpet a month later about her sister's special night.
A photo posted by Jamie Lynn Spears (@jamielynnspears) on
Over the years, no amount of global success has made the pride that Jamie Lynn has in her sister's accomplishments feel any less personal or genuine—and she appreciates that having such a famous sister has opened a lot of doors for her as well.
In 2014, while promoting her debut country album The Journey, she told radio station Kickin' 92.5, "I'm proud of my sister. She's worked hard to become extremely successful. It makes me proud, but it also gives me an outlet to prove who I am as a person and what I love."
And of course, in addition to being there for the big moments, the sisters are just as content to enjoy life's small pleasures together.
Just a week ago, Britney Instagrammed a pic of Jamie Lynn with the caption, "When I'm with my sister she makes my stomach hurt so bad from laughing!"
May there be better times ahead for the Spears family—but at least they have each other to hold onto in times like these.