You might like to try hand sanitizer! It worked for me when I did exactly the same thing. That darn sharpie drawing takes a really long time to completely dry. Strongly suggest that you make a mess with the sharpie on a scrap of fabric first and try to remove that before trying it on the quilt. I originally found the tip online (sorry I can't recall where). It did not specify a particular brand - hence the testing. Best of luck from here in Australia.