I dunno man, I think you're wasting your time there and her friend backing up her story means squat. Women will back women up and rationalise lying to a man as "protecting him from the truth" and what not.
My suggestion though would be to go out with her for a night out, go back to hers and get in bed with her as you normally would and try initiate sex with her. You'll know exactly what she wants from you in that moment. Either she's up for it or isn't. Atleast you'll have your answer then. You should know straight up if it's LMR or if she genuinely isn't interested in having sex with you.
While lying on the bed with her(Don't wait for her to get in her pjs -- and if she normally wears pjs get rid of her. Women who sleep naked are so much better in bed!

) start off talking to her about the night or something you can joke about, turn towards her(Her on her side towards you is a good sign) and smile while joking. If she's looking at you in an inviting way just go for a kiss. She should return it then simply turn her on her back while kissing her, slowly caress her stomach and side(Just above the hip) and move your hand around that area slightly. She'll give you signals then just go for it, slide a hand up to her breast, taking her breast out and while you're doing this bring your other hand to the back of her head and start kissing the side of her neck(Which ever is more comfortable to kiss). This'll drive her nuts then you can start moving from her neck to her chest and let the rest fall into place. You'll know when you go to kiss her what she wants. She'll either stop right out or return the kiss or she'll resist but seek it.
Women want sex. Women enjoy sex just as much as men. If you're laying in bed next to her on the regular and you're both sleeping then, to me, there's nothing between you. Any woman i've slept beside in a bed has not been able to keep her hands off me. It's not because i'm a sex god or the most sexy guy around(I'm not, i'm actually a plain looking guy) it's because there's been chemistry between us and excitement, excitement that no matter how long i've been fucking them it's always on even if i've stayed with them for a week or two. If you're in a position where a woman can go to sleep in the same bed as you time and time again without seeking some sort of sexual encounter or even a kiss then there's no passion for sex there and all relationships, at their core, revolve around sex. If you don't have that sexual excitement you won't have a relationship.
If she's not into it I'd move on, use her as arm candy in clubs and continue the friendship. Maybe then in a couple of months she'll see you in a different light when she sees you getting the attention of other women.
At the end of the day you've built rapport with her, you've DHV'ed(She's enamoured by your lifestyle) so all that's left is the sexual component.
Women want sex:
http://www.youtube.com/watch?feature=pl ... l7rc#t=59s