What is wrong with some women

Recently I broke up with my gf ..We were together for a year short enough I suppose ..I'm 30 and she's 23 didn't think the age gap was a problem at the start but did notice a few months into it there was a difference in maturity ..I new this girl for years and new that she was in an abusive relationship for a little under 2 yrs..She also had a child with this lad ..Anyway her ex done work on my car so I called down to them an odd time ..Called down one day after she had ran him after a fight..Followed by the next day ..And eventually started kiping on her sofa because she was afraid on her own plus I was living in a dump at the time so it was handy..We got along great wasn't really interested in a relationship but she approached the subject after a couple of months I said fu** it I'll give it a go she was hot and seamed nice..Officially moved in with her we were a great couple i got along great with her son..

She was traumatised after this lad..He nearly killed her in the car when he got thick..Beat her ,called her names the works...Anyway she seemed to be getting over the worce but I started getting cold feet ..She was needy jealous and young ..I did tell her she needed to back off but she'd get upset which was never my intention..Eventually when the lease was up in the house I told her I'm moving back home for a month..She was ok with this she moved to her homeplace as well and we did talk about sorting things out..

Our biggest issue was sex..Me being 30 and her 23 I didn't want it twice a day..Twice a week would be more like it ..This did annoy her..We never argued about any of this we always just spoke about or problems it never ended on bad terms..She called out to me we spoke on the phone same as usual..

Then I noticed she started pulling back ..Not answering my texts ..Later found out she was back with her ex ..Like wtf..? This girl was tramatised by this lad she told me she hated him and i had no reason to not believe her..I know I told her I wanted space and to move home but is that a reason to get back with an abusive ex ..

iv met her twice since and she had to rush off after a half hour so I gave up totally on even wanting to be friends with her..I'm not heartbroken my days of sobing over women are long over i hope anyway..I do obviously miss her and sometimes get that sick feeling if i let my head run away ..im just annoyed..confused as to what goes on in some people's heads..Was it the sex ? I did notice she was more loving towards me after sex ..When we had sex it was good but she just wanted it a lot more than I did..I mean I know having kids with someone holds you together for life but I would never go back with my ex and we have 2 kids together ..Sorry if this is all over the place..Iv never wrote one of these before and I can't really talk to anyone about it