A girl I use to date, texted me around 6 months ago, keen on meeting for sex. We hooked up, etc. etc. After that, we had zero contact for another 6 months. Just the other day, I get a text from her "hello, how is everything" after texting for a couple days, off and on, she never replied back. During our texting, i tested the water, and said she was just looking for chit chat, not sex- which is fine.

Is my ex just being sincere, or what? Every blue moon she'll pop in and make some effort. If we could just be friends that would be fine

I do something very similar over and over again, however I'm a guy. Whenever out I'm out of a relationship, or if I'm just our of options for some time, I tend to text / or fb message my ex GFs or any girl I used to have sex with.

It makes handling a break up easier for me and it's easier to text someone you already know than going out sarging, clubbing and finding new girls. Also a lot cheaper, LOL.

This pattern always ends when I get a new girl, than I don't want the old ones anymore.

This could be the same with your ex: she was bored, she liked the sex with you, she texted you, you guys had sex. Then she got back together with her ex or she found a new guy and she stopped texting you.

Just my 2 cents