Help from singers pls.?

Question:

Help from singers pls.?

my sister has been obsessed with singing since she was a kid, and her voice is kinda like christina or mariah - shes really loud and she got the waves n stuff - but the thing is - when it comes to the high pitch/screaming part - she really cant do it.
what can be done 2 fix this problem? anybody?
thanx.

Additional Details

8 months ago
Thank you guys so much

Best Answer - Chosen by Asker: 8 months ago
Thank you guys so much