October Novel Prep Challenge

I've had this book idea for years since Nano 2014). But the more I've worked on it the more I realize my main character's backstory needs to come before the story I'm itching to write right now. It explains so much about her and why she is who she is and why she does what she does in my current story. So I'm caving to the idea that I need to write a different book about her first.

In the book I want to write (Now book 2) A second character will also become important part of my main character's history, probably from the very beginning since I'm now splitting this into more than one novel... Though technically will have nothing to do with her in what will now be Book 1...

So my question is, is it possible to write a book one involving two different characters living completely separate lives, who will not meet until book 2? Has this been done before and how would I go about it?

My thought is they would need to be struggling with the same basic issues (in obvious different ways) leading them to meet in Book 2 and thus having them collide and affecting each other so vastly in Book 2...

Is this idea feasible at all?? Any ideas how to pull it off? Alternating chapters? Etc....?

This has really changed my entire Project that has been boiling in my head for 5 years.

Maybe I should just work on my other book idea since I've been focusing on 2 books this octoberprep (which is now trying to split into 3!!!)...