I actually gave up on trying to groom my lot. They wouldn't sit still, and I end up being scratched and with stray hairs flying all around me while the actual cat got away.

However, as it is probably better to groom them, I suggest first getting her acquainted with the brush, let her mark it (by rubbing against it), smell it etc. Then try to find the cat in a particularly good mood, when she's just settling purring curled by you, and then very gently start combing her. Hopefully this way she won't feel threatened. This may take a few rounds, but be patient.