Brews my ex just popped up at my crib

i moved back in with my folks when I left the military and we just chopped it up for about 30 minutes. Mind you the last time I saw her was about 3 years ago
-We dated at 16, we 26 now. She cheated back then
-She went through a phase where she was stripping and doing coke

dropped out of school, but now she’s back taking classes.
-My pops would tell me all the time her moms was asking about me, I brushed it off. Tbh I don’t want to deal with someone who was stripping and doing coke
I’m just thinking out loud about why she was 1) pop up unannounced, and 2) still keep in touch. We grown now, why keep tabs on someone from years ago?