Do schedule a test drive if you can. I am 5'6" and was worried about the non-adjustable seatbelt on the I-pillar. Most every other car, at any price, has an adjustable sliding (higher to lower) seat belt mounting point there. Tesla does not. I have no idea why they don't care about that feature. The seatbelt height did work out for me OK, but YMMV.
The seats themselves do offer a lot of adjustability for height and distance. So does the steering wheel for height and tele. Then see if the accelerator and brake pedal work for her, and I think only a test drive will solve that. The acc. pedal requires firm pressure to moderate the balace between regen and moving forward. My wife has a problem with that (pedals), and we will try to work around that somehow.
Short of a test drive, maybe just sit in one at a Tesla location first?