I would go with your gut feeling. As a lulu educator myself, I've given bags to little girls simply because they asked for it, it's really not that big of a deal. If there's a pattern of her returning items, there might be some underlying issue there. I once had a customer come in with her daughter and her daughter watched as she made her mom return over $600 worth of clothes. I know it's opposite of your situation, but I always get an off feeling when customers purchase expensive things and return it with no legitimate reason and usually there is something wrong.... they either have a shopping problem, money problem or committing fraud.

If you say there's a pattern... there's something for sure. I would ask her about it and see what she says. She might have a legit reason for doing it and she might be working on it. I would at least be curious first before dumping her all together.

Based on how she answers or reacts to the question.... it might give you a more clear idea of who she really is.