It's a tough one. And you have to be super careful when coming out of it (EXHALE!). I actually injured myself doing this (muscles between my ribs). It's unlikely that it'll happen to you girls as you don't have the previous injury that I do from rowing boats and having a rib cage that doesn't flex as much as it should, but I thought I should still warn you to exhale and try to come out with as much control.
I love how different people struggle with different moves. Took me four months to learn wrist seat (hello boys), but I got a yogini on my first try (before I could even invert).
Happy training girls!