In fact, Rainbow is so into it that she's already got a name selected, but whether her parents actually go for it is another story.
"The name she picked out was Strawberry, so I don't think I'll go with that!" Madison said.
While it's doubtful Rainbow will get to name her second sibling, she could get another chance. Madison revealed that she and Rotella would like to keep having children.
"We'll see how this one behaves, but my husband wants a lot of kids, so we'll see," Madison shared. "He's like, 'Let's have six!' ... We might end up adopting some because I don't know if I can push them all out."
The New York Times best-selling author has officially put her past as a reality star behind her (she says she has no desire to do a family reality show), but her past dating life is brought to light in her new book, The Vegas Diaries. Madison admitted there was a time when she feared the book might have gotten too personal.
"At the last minute, as a writer you kind of get stage fright, and you're like, 'Why am I putting this out there?'" Madison explained. "But that's the point of sharing an authentic story is really writing about the things that make you feel, whether they make you feel embarrassed, happy or sad or angry. If I would have taken it out, it would have been boring."