My 2 cents. You agreed to do it when your daughter asked. You are really doing it for your daughter, even though it is to be given to your sil. I like the idea of writing a scripture verse on the back-where he can see it, maybe part of the signiture as every quilter should sign their work. Maybe ask the Lord to lead you to a verse that will be effective in touching your sil. Trust in the Lord for His timing- a hard thing to do too sometimes, and ask for protection for all the family.
AND then in the future if your daughter asks you to make something for him, just tell her that you can't, that your heart isn't in it because of his behaviour.