I would set her up an email address if I were you. She is going to need one (most likely) anyway, so you might as well help her with it, and make sure she shooses a sensible email address.
Either- set up an additional email adress through your internet provider (most of them let you do that)
Or go to something like hotmail or googlemail and set her up with a free email address.
Both my 13 and 12 year old neices have email addresses. You also need an email adress to set up a Facebook account (you might not want her to have one of those yet- but I am sure she will soon be wanting one!) Both my neices have Facebook accounts- they are young enough that they have added all of their family as friends, but I am sure that will change in a few years when they don't want us to see what they get up to!
Beth