Loke is right, you need to engage both the target and the obstacle.
Sounds like you did pretty good for a first time. If you find you're too tall and she can't hear you, speak up, you need both the girls to be able to hear you for the mentioned reason. If she can't hear you even when you're speaking loudly, try to make her come to you, just beckon her in when she says she can't hear you.