Again according to Disneys own site you will be fine. If you want go to the disneyland website, and go to tickets only, when you click on So Cal tickets it will ask you your zip code, use your sisters or maybe a famous one you know <Hint, Hint 90210> and it will show you the ticket prices. When you click the tickets for information, the quote I posted is right there.
I also know its fine because my Mom bought My Aunt and Cousin tickets a few months ago, my Mom had an AP so only bought two adult tickets, neither of which she personally used and they only asked for her ID.
If the website said something different I would not tell you to try it, but in this case DL has a clear statement so you will be fine. BTW if you are still nervous the same case applies at the ticket window, you can buy up to 8 tickets (not Annual Passes) on one So Cal ID, but I believe they must pay if using a CC.
Good luck and don't worry!
PS- They will never ask for your ID at the turnstile unless they don't think your pass belongs to you (AP's) the only time they will ask is at the ticket window.