How does the UCI enforce a fine? When you race do you have to sign a contract stating that you will pay any penalties, or can the fine be seen as "must be paid before competing again"?
You don't have to pay it, but you won't be racing again. As a former USA Cycling official, I'd occasionally fine riders for infractions (usually $20-50 payable to the youth rider fund). They didn't have to pay it, as I had no enforcement authority outside of bike races. However, if I saw you next week and you hadn't paid the fine, you won't be at the start line. I couldn't make you pay it, but I could prevent you from racing.
She has no fine, only if she wants to cycle again, then she has to pay the fine. The UCI can't force it as she's not a member anymore and the UCI isn't a court