She probably just needs time to get used to the new bike as well. Once that’s done, the choice of trails shouldn’t matter too much. That bike sounds nice. You could always upgrade the tyres to something really grippy, as I imagine, like most new bikes it didn’t come with anything special.
A few trail centers have fireroads as well as singletrack, so you could just stick to those and then delve into the twisty/bumpy bits when you feel like it.
Good luck with that. My wife went over the bars and bashed her knees at Llandegla last Sunday, and isn’t keen on doing more, so I’ve got to work on that now 😉