When I started my new novel about a retired assassin who finds herself without a clue about how to make friends, I wrote 10,000 words of back story for each of the four women in the book. I wrote almost 200 pages of alternating point-of-view before I acknowledged this wasn’t working and switched to a single POV. It was a first draft, and all the garbage was permissible. That’s what my second draft is for: fixing the overall arc of the story, deleting the stuff that doesn’t work, and dumping the prose of which I am proud but doesn’t serve the story (also known as killing your darlings).
Katya sounds fascinating! I can't wait to meet her. :-)