Carrie Fisher was "grounded" when she became a mother

Speaking to the New York Post's Page Six column, he said: "When Carrie became a mother it grounded her very differently. Looking at Carrie, ‘she’s going to be a mother, holy mackerel what is that going to be?’ But what really happened …

"Obviously Carrie was a unique mother, it’s what kept Carrie with us. I think we would have lost Carrie long ago, long before if it hadn’t been for Billie."

And Todd believes that if Carrie was alive, she would have adored Billie’s son Kingston.

Speaking about Billie's son, she added: "Carrie would have continued that, she obsessed over Billie. She shared with Billie herself and I think that would have continued.

"I mean look what happened to my mom, she bought the house next door to Carrie to be close to Billie. Debbie (Reynolds) and Carrie weren’t even talking at the time. She would have bought the house next door so to speak."

Todd previously revealed watching 'Star Wars' helps him to cope with Carrie's death.

He shared: "A lot of people asked me when they died, 'How do you deal with it?' Part of it is the faith that we all shared, my mother, my sister and I - the idea that we shall meet again, and they’re not far from you. They're just in a different space or a different dimension. There are a lot of words you can attach to [that]. The word 'force', for example, is ['Star Wars' creator] George Lucas’s choice word, but you could interchange the word ‘faith.’ I find a lot of that comforting."