Re: mustache
I dont think its right for her to feel so conscious at such a young age but do understand the teasing aspect of it.
Try to use something subtle and natural to help the hair problem but do NOT get her into plucking, threading and such so early.
The jau ka atta thing is pretty common and good. PM Gina for it...my grandmother did something similar to me when I was really little. She would rub a small pera of atta all over my face and arms...it helped me a lot. I didnt know why she was doing it and would get so annoyed but now Im so grateful she did!!!!!