So sorry that someone took your quilt. It's my opinion that someone who would do that, did it out of a sense of jealousy and entitlement. If someone really loved it and thought they could do that too, they would ask what the pattern was. On the other hand, if they didn't have the skill to make one, coupled with a sense of entitlement that THEY deserved to have such a quilt...
I hope that you will get it back.