You're right that she shouldn't have stood on the seat and should have thanked you for your help. That said, I can certainly sympathise with her. I'm slightly on the short side myself and find it a little humiliating if I need help from strangers to get items from the top shelf at supermarkets or put baggage in overhead lockers on large aeroplanes. If my day is going okay, I can deal with it, accept that it isn't personal and ask for help with good grace. If I'm having a bad day, though, I get cross with a world that (in this frame of mind) seems to be unreasonably neglecting me in the design of building and planes, and consequently impeding my status as an independent adult -- so in that frame of mind, I'm sorely tempted to climb on things and glare at people who offer help. I don't. But I understand those who do.