Call her and let her know the first quilt you brought is for your mother at the end of May and you need it at least a week before that. That isn't being pushy. If you just wait for her to call it may continue to stay at the bottom of the stack. I do LA quilting and I don't mind my customers calling and asking the status of their quilt. I usually give them a time frame when they drop it off and some call a couple of days ahead of time just to check if things are on schedule.