How old do you have to be to buy toys from Ann Summers?

My 15 year old sister has ordered, and received, a 'Rampant Rabbit' off the Ann Summers website and has shown it to me yesterday. I didn't know that you could order these types of things if you were her age or not? Should I tell my parents that she has one of these things or not; I think she used my elder sister's (21 years old) credit card to do it, since she hasn't got one herself and my oldest sister has ordered underwear from them before.