My Friend stole my underwear and I decided to cut contact. Am I overreacting

Ok so me 20 F has had this friend since childhood she's the same age as me and we've always been close I recently noticed that a bunch of my underwear goes missing when she comes over but I didn't think anything of it. I also recently starting dating a guy and one day he was walking into my place at the same time she was leaving and she dropped her bag and he saw she had taken about 5 pairs. She's a wealthy girl so it's not like she needs them and when I confronted her she denied it and eventually claimed she just liked them. About a week ago I see a post on Facebook Marketplace selling 5 of the same pairs that had gone missing. The post was also super weird saying something like fresh underwear for sale. I'll say this again she's very wealthy and has a trust fund and already works at her dads company. I decided to just report the ad and blocked her. Am I overreacting?