Mark Davis/KCA2013/Getty Images for KCAJennette McCurdy doesn't have to mourn the death of her mother alone.
Her Sam & Cat costar Ariana Grande tweeted her condolences and support after learning that Debbie McCurdy lost her battle to cancer.
"[R]est in peace Debbie McCurdy one of the most beautiful brightest souls and kindest hearts this world has ever known, I was blessed to know u," the singer wrote on Twitter. "times like this remind you of what's really important."
McCurdy, clearly touched by her friend's post, responded, "@ArianaGrande thanks for being by my side and showing so much respect to my mom."
"I love you more than you know always," Grande wrote back.
The Nickelodeon stars are best friends, and were even planning a sleepover for the day McCurdy suffered her tragic loss.
"Ariana and I just planned a sleepover for tomorrow we're going to be in New York together and we're going to go over to her apartment and sleepover," Jennette told E! News at People Style Watch's Hollywood Denim Party at the Palihouse in West Hollywood on Thursday, Sept. 19., one day before her mother passed away.
"We share everything. We always go through, like, boy situations at the same time, so we both had new kind of romances over our break, so we've just been kind of catching up on those," she added.
"We keep each other on track, we don't really talk much about work stuff, because I feel like we talk about that so much with other people that we like to keep it to family, and just personal stuff. It's all completely personal, what we've done with our friends lately, where we're going, what we're getting into, clothes."
The 21-year-old also praised Ariana for her strength and dedication.
"She's extremely strong-willed and she will do whatever it takes to get what she wants if she really believes in something. I think that's such an admirable quality to have and I look up to her for that. And I think that's something, working with her now for a year and a half, that hopefully I've adopted a bit of and I hope to get more of it as time goes on."
You are definitely one strong young woman, Jennette.
—Reporting by Alyssa Toomey