What will you do if your in my situation?

i have 9 cousins, 6 guys(elder ones) and 3 girls(younger ones), i am very close with all of them except for one, which is a girl(second to the youngest), my i am close with the other 2 girls, i don't know if that one hates me but i can sense something awkward, that cousin of mine is very conservative, yeah she has the looks and all, but when she comes to my house with her 2 sisters, she acts even more conservative, as if i am a lustful maniac or the like, im not guilty or something but, the way she act, you'll feel like one(know what i mean?)... another is, she won't even dare to touch me(by any means of physical contact) or somewhat be near to me or be touched by me(this does not really happens all the time, but MOST of the time it does), as if i am having a very contagious disease.But as a person, and to other people in our community, she's actually nice, a very industrious, intelligent and loving daughter of her family, actually among all 10 of them she's my favorite but by the way she acts, does she really trying to show or tell that she hates me or simply tells me to back-off? or something? i have done everything to be close to her, i have been very generous and all, im also giving a very unconditional love to her, but , im so tired doing i dont know how long i'll be able to give that "unconditional love" her because i have done all the things just to be close to her but i think she just keeps pushing herself away from me, could someone please help me?? what should i do? should i give up? or wait until she realize the brotherly love im giving to her? (because im the only child in our family,(and im longing to have a little sister))