I actually embrace the purse holding duties.
Sometimes I'll just throw random stuff in there (stamps, postcard from Florida, bloody glove) and see how long it takes her to find it. If we ever accidentally stumble onto the set of Let's Make a Deal, we're golden.
And if you ever get tired of holding the purse, just put some expensive lingerie in there when she's not looking and make sure you're nowhere near her when she sets off the security alarm.
Before you know it, she'll learn to never trust you with that responsibility again.