In the past I have used my grandmother's mixer to mix my frosting. Now I am too far away to borrow it and I will be making my daughter cupcakes for her birthday. My question is: Will my frosting be ok if I use a hand mixer or a food prossesser? Does it matter what kind of mixer I use? Thanks for your help.

A hand mixer is fine... I don't know about a food processor. Haven't done any baking with the food processor yet but have seen famous chefs use them to knead or make batters.

If you mix it with something that pulls alot of air into the bc it will leave air bubbles....if that is for cupcakes I don't think thats a problem.