K.A.
I keep a pack of post it notes in my bag to put over sensors on the wall and put some toilet paper over the ones that are on a bar. This keep those things from flushing every 2 seconds. I don't take the block off until we're totally ready to leave the stall and it's the last thing I do before unlocking the door. What I would suggest is to use the toilet before her with the blocked sensor to show her it will no longer flush, maybe find a quiet bathroom when she doesn't need to go really bad and show her how it doesn't flush any more. It wasn't long before my son was OK with it finally.