If she is improving in other areas except naps thats great!
I had other parents saying things to me at drop offs/pick ups about being worried their child had to listen to dcg scream all day. That was my turning point. Didn't want to risk losing my full time families for a dcg who was 3 days a week.
For naps, try putting her in the furthest away room in the house with a loud fan or white noise machine. It may take a couple of weeks but she will get it. If no improvement in 2 weeks you may need to make a decision. Afternoon naptime is crucial!
