Just wash it again (and maybe again!) with some Shout Color Catchers in the machine. I probably overdo it, but I use several with a regular size quilt and I use 4-6 for larger quilts that I have to take to the front-loaders at the laundromat.
I'd use some OxyClean in there, too.
Don't dry the quilt in between washings - just keep washing until the pink is gone. Hope it only takes one or two! Good luck! :)