Hi Boo, yep I was in total state of shock when I found out I was expecting identical twins (they're 17 years old now btw)
Was so terrified that I would get them muddled up that I kept hospital I.D. bracelets on them for days! Mums intuition takes over though, and even when they're identical you soon realise how different they look to those close to them. A word of warning, you may find as they grow up that the uninitiated treat them as a unit, eg sending them one birthday card,calling them "the boys" instead of by their names, its annoying, but you will know that they are individuals.
Hope you and your daughter have a lot of fun with your boys:-)