That's exactly why Todd is a little protective over his 24-year-old niece, especially in regards to who she's dating.
Carrie's brother chatted exclusively with E! News at the Las Vegas Film Festival ahead of a screening for Bright Lights—a documentary about their family—during which he was candid in expressing his feelings about Billie's current beau, Taylor Lautner.
"As any uncle, you're suspicious of the guy hanging around your niece," he admitted. "She's cute and all that. She's had other boyfriends, good boyfriends, but I'm certainly going to give that guy the extra look-over. I don't give a s--t what his background is."
However, Todd can't help but praise Taylor for his support.
"The truth of the matter is, the guy is pretty spectacular. He's a really deep person, and he has supported her amazingly," he continued. "He's stepped up and acted like a husband would act. Not that that's what's going on, but it's just an amazing support system for her, and I'm glad he's in her life. That's not easy for me to say, if you think about it!"
Other than being protective over her, Todd also opened up about another side of their relationship.
Following Debbie's passing, they've been going through her storage units full of collectibles and memorabilia.
"She has huge warehouses full of stuff…Now that she's passed we've tried to go in and figure out what are we going to do with all of these things," he told us. "She collected many different things. She had a very eclectic sense about her."
He explained one of the things that meant the most to him was a cigar box full of artifacts from her time spent entertaining the troops in Korea.
"Also, I have all her writings and her love letters," he added. "She wrote letters to Carrie and me that were supposed to be taken out of the safety deposit box on her passing. Those letters are beautiful and deep."
Since Carrie has also passed, Todd is handing the letters off to Billie.
"I will [pass them on to Billie]," he told us. "She and I are the last of the Mohicans, so to speak, so we've been exchanging a lot of things like that."
He continued, "The cool thing is I can turn it around and say, 'Here, Billie, look at this beautiful note from your grandmother.' So there's a beautiful side to life. It is part of life, but it's also heartbreaking at the same time."
Finally, other than taking care of her daughter and her keepsakes, Todd wants to continue Carrie's impact in the Star Wars movies. His hope—which he says would have also been Carrie's hope—is to see her featured in future films.
"I made a comment at an interview a while back where I said I would like to see Carrie continued [in Star Wars], and with technology you certainly could," he explained.
Though Disney originally denied the idea, Todd thinks the company will change its mind. "I think they've gotten so much push-back that I'm hoping they'd reconsider it. I think Carrie would like it continued in some way."
Watch Todd's full interview in the videos above.