Good reason to sew at her house next time, or ask DIL if can use her house to sew at, she would probibly understand why, then just bring what you want to use even if you have to bring quite a bit to get the job done, no different than going to a class. Keep in mind, I give quite a bit but those things are my choice, the mooch thing gets tiring real quick.
OR
Just say no !! Have plans for that, no doubt did when you bought. Good Luck