Been through something similar with my other half.
Found skills sessions to be the best, an independent person is really good to provide confidence and stops trail side arguments….
Also I would re-consider bike size. We started with a T-130 which on paper was the right size but her new bike is slightly smaller and its helped a lot. Long bikes are great if your skills are good, but I believe for confidence your better with a nimble bike as flat out speed isn’t really the concern.