Too much sugar is not the BEST thing for any of us! And marshmallows are almost 100% sugar! Still, a little treat now and then...can't say I'm not guilty of that myself every now and then! The only word of caution is this. As with children, marshmallows, especially the big ones, are a common cause of choking. So maybe pull off a few little pieces and feed them to her that way, instead of a whole one. Not too much now!!