OOB?

[Ralph Stubenthal]

On a throwin, A1 throws the ball but it is intercepted by B1 near the sidline. B1 is immediately covered up by team A players. A1, while still standing on the boundary line, reaches up and touches the ball in an effort to take it away. There is no foul nor held ball but A1 is just simply standing oob still while she touches the ball. Even though B1 had possession of the ball and A1 merely touchwed the ball, I called OOB on A1. Good or bad call? If bad, what should I have called if anything? Ralph.