Women don't want you to know this, but returns are free.
They like buying things, not having things. They'll buy a million things they don't want and will never use, and be totally happy with those purchases. It's about the act of getting, not the utility of owning.
Simply keep all receipts, and return everything yourself. She'll never know. Between Target, TJ Maxx, and Home Goods, I've returned 847 items.