I don't see why you can't make a trade with her. I think she will owe you a few more hours than what you'll owe her. My DMIL does taxes and barters with plumbers, painters, carpet layers, etc. It works out well for all involved. I think it's a nifty thing to do.
She wants a quilt and you want personal training. I paid $25 an hour for personal training where I live. I would have swapped for a quilt in a heartbeat. I think it's a great idea! Go for it!!!