You "ran into her"...does that mean you just met and talked and now you're terrified? CR has some testosterone shots cheap for this type of problem.
If you banged her and you liked her, text her back and say you're now back in the USA and your wife snoops, but you'll keep her number and see her, pay her and bang her upon return, but not if she keeps bugging you.
For that matter, you can block her on Whatsapp and then unblock her and contact her when you return if you want to slam her again, and maybe deliver some "revenge sex" hard rear pounding for annoying you...
If you banged her, and she was no good or mediocre and you don't want to repeat, tell her you had a good time but found a favorita who only charges $30 per 2 hour session with dfk, bbbj, gfe, 69, etc., if she agrees to match that, give her another try next visit, otherwise, say adios, amiga, then block her.
Unless you caused a problem for her that you're not revealing here, you're not worth her time to try to mess you up, but she smells a newbie who worries about petty things like this and thinks she can take you.
I know more than a few old time "pros" here who will laugh at your plight, but they're shelling out money to hoes that fleece them good with impunity. Don't become one of them.
Be like me. Lie, and be rude. It's always worked.