If you are going to train her here are some things to take into consideration:
Make sure she has
1. Full knee flexion and extension
2. She is able to fully carry her weight
3. She has minimal swelling
4. She has medical clearance
5. She is at least four weeks post-operative
6. She has no anterior knee pain
Having said the above, if you are going to approach training her using Pilates, you’ll likely have to utilize the reformer, stability chair and cadillac.
Best to you.