Dd is 12 and just recently has been getting really greasy roots. I don't think she's bothered but I well remember the misery of being a greasy haired teen and I want to save her any embarrassment or teasing. At first I thought she perhaps wasn't washing the shampoo out enough as the shower water pressure is pretty rubbish and I think that's probably a part of it too, lots of build up. We're in a hard water area too. Any suggestions for a nice shampoo that might work?