Aaaaaaaargh yes its complicated but please listen.?

ok.The girl I like is called meri. It's not 'like' as in woooah shes fit, It's a sort of deeper thing, you get the idea. Anyway, we're pretty good friends, I don't think she thinks anything bad about me. (no more than I know any of my other friends do) No arguments or anything, perfectly good friendship. Now obviously I want to ask her out, I don't know if she likes me. Also, theres 1 other thing. one of Meris 3 better friends (lizzie) has a bro (alex) who is very socially inept(verges on autistic/ asbergers, no piss take). he has no friends so i became his 'friend' with an ulteriour motive of gettin him a life. but ma m8 luke is very cynical about it and is a jerk to alex. (sometimes with good reason) But lizzie is very protective of alex and tarrs me with the same brush as luke. This then reflects on me badly in lizzie's, and therefore probably meri's eyes. I know meris friend alice ok as well. Neva told anyone this, so i thought a random bunch of strangers was best. Advice?Ideas?