Should I ask her out?

Ok, about 6 months ago i started talking to my Friend's girlfriend. We immediately got on very well and i met her a couple of times with my friend there. However, my friend has had a personality chance since then and after splitting up and getting back together about three times, they have finally decided to pull the plug and my friend swore on his life he'd never speak to her again. The girl has been on the phone to me every night for quite a while now and our friendship has got a lot stronger. She had come round my house once before and got on really well with my family which is a good thing. She came over today and we watched a movie.. I was sitting away from here on the sofa but she made me like sit really close to her and snuggle up to here. It was really nice but i didn't go any futher as i know she still is upset and possibly still has feeling for her ex. I don't know whether you can actually love someone at 16 but I have feelings for her that i haven't had for any other girl. I'm not really looking for a relationship atm but i do like her a lot..