Yes, it's a Z50ii. She currently has the Z 12-28 and is using her F mount lenses with an FTZ. IMO, it is a big step up from the D3300. I haven't used it enough myself to be able to say absolutely, but from my little bit of playing around with it, I would say the AF is good to very good. It has the same 3-D tracking and object detection options that my Z8 has. It also has lots of features like auto bracket, focus stacking, pre release capture, and focus peaking, to name a few. IMO, it would make an excellent entry level wildlife camera. It should be very capable for most other types of photography as well. My daughter has been very happy with it so far, and she was very reluctant to switch to mirrorless.
Perhaps someone else with more personal hands on experience could chime in on the AF capability.