You won't get an empty seat on the flight these days in coach so you'll end up holding your girl in your lap the whole way. If there are two adults flying with her, it's possible but not very pleasant. I've done it with my boy at that age to Frankfurt from Minneapolis. I'd do it that way again, but my family is pretty experienced with international travel and I knew what I was in for. It's far easier on the way to Europe on a later flight than on the way back when the toddler's awake.