If it's clear she's not going to get there, she has an obligation to avoid or minimize conduct. You don't have a right to take out the player playing the ball, and that's ALWAYS called a foul on the attacker if the keeper gets there. If she misses, or you beat her to it because it's lower than she thought, it's fair game. But she's got her entire length of arm to get there ahead of you with just your head, she's going to get there first if it's above head level. You don't get a license to take out the keeper just because there's a cross.The attacker has a right to go for the ball, doesn't she?