We know confidence is a big part of it BUT as an athlete gets back to tumbling from an injury they should ease back in to the skills and get a chance to see how it feels to hold weight and push off of her arms/hands. Not sure what she has done to this point? I would start with putting weight in her arms against wall/pushup position, work into handstands and through basic tumbling progression cartwheel, RO. When she is comfortable with that work on standing BHS and REALLY focus on good technique, when you use good tecghnique it should not put undue stress on the body and will help avoid injuries in the future. Good technique will make tumbling feel easier, give you more control of tumbling and transfer energy to next skill also takes less energy when tumbling; all of these things should improve her tumbling through the rest of her progression as she gets back into running tumbling/ROBHS and in turn give her more confidence in tumbling.
Hope this helps? I have been coaching tumbling for 16 years across U.S., Canada and Europe all levels and have had alot of success helping athletes return from injury and work through 'blocks'. If I can help in any way feel free to shoot me a message.