I bought and installed Lion on my iMac yesterday. I have a Macbook in also but that's primarily used by my mum who has logged in to the mac app store with her itunes account. Can I use my purchase of Lion and isntall it on the Macbook? Is this legally allowed? It's technically my machine but has her login details. Is the downloaded .dmg for Lion saved somewhere on my iMac? Can I just transfer that over instead of re downloading on hers?