Andre Galvao deep half-guard killer.
Generally the arm-drag from half-guard is a great go-to.
Also have her learn the pentagram choke. It's a great option from there. I also as I'm taking the back, have a decent success rate with sneaking in a triangle or reverse-triangle; I think some people just forget that you're not always going for hooks when you get their back.
Teach her a good sprawl, then have her drill with and without a live partner, someone shooting in, her sprawling and her taking the back from there.