My two friends have split up - driving me insane!?

It's a same sex relationship they are both 18. Things moved insanely fast & they moved in together after just being together for under a year. They both became so wrapped in one another & did not socialise beyond one another. They split up because there was to many arguments & they were loosing out on their teenage years - this was the choice of one of my friends who insists she will not be getting back together with her ex that they need to move on & she's happy that way yet she still she's her ex everyday, it's as if they are still together & it gives my other friend mixed messages because she is clinging onto the hope if then reuniting as a couple & only bothers about her ex only makes the effort to see her & does not bother about her friends. What do I do? I know it's not about me but it's becoming unbearable she constantly posts blogs about how shes changed that she's sorting everything out yet when I talk to her ex she goes on & on how they will not get back together?