She may have unlocked Rhodey, but that doesn't make her really useful. What it means when people point that out is would the film be effected if they were removed entirely. In her case, no it wouldn't. Now, had other minor roles like Fury been removed, the film WOULD have been effected. He was essential to the father angle. However, she really had no true purpose in the film. When you're putting characters in a movie, big role or small, all characters should have a purpose for being in the film. Widow seems more like a distraction than an addition in IM2, and given for all her screentime she has no character and basically hits a few buttons, they was useless. I am not saying that to make IM2 out to be bad. I like the movie, but her lack of things to do and overall purpose passed being hot is something that sticks out about it. I still say BR gets unjust hate. I like it. I don't use RT unless it is something I am on the fence about seeing, and even then, I don't let reviews sway me if I end up watching the movie. However, too many people use it as a way to justify their opinion, and that is not how you should use it.