Thanks for the feedback y'all. I had checked the used market first and didn't see anything that was going to work without spending more than I wanted or having to put more work in than I'd be able.

I took them to the LBS and let them try the bikes on for size. One went with the Myka and the other went with the Marlin. My girls are both 5'4" so we went with medium frames. Picked them up today as the LBS put them on sale yesterday. It was nice of them to tell me about the sale so I could wait and save $100.

So, hopefully I've got some new MTB fanatics. Now I need a way to transport 3 bikes lol