How can i get back with my ex?

[James]

We broke up after only a month, and idk why.
We stayed friends, but this wasnt enough for me so i got kinda mad and i guess just ignored her.
I started to be nice to her again like a week ago and we kind of got back to being really good friends. But whenever i try to flirt with her she doesn't really flirt back.
Then on twitter shes posting some things about being lonely and thinking about someone shes been with and things like that and retweeting relationship stuff, around the time i started being nice again.
We used to text all the time so i tried texting her a couple times but she wont text back. She's only texted me a couple times in the last month. I texted her again last night with no response
Now its christmas break, and i really want to see her over break but i dont think she does. Should i try again to just stop talking to her? We 16 by the way.