My budgie has been biting?

lately one of my budgies have been biting me a lot and recently when she climbed onto my hand she bite me and i started bleeding just a bit so every time i come to play with the newer budgies( been here 2 or 3 months so not really new) or with her older cage mate she starts biting me Dx I'm not letting my brother play with them being afraid he might cry if he gets bitten by her. Her ceres is blue instead or pinkish red.