I concur with Santa Sangria, as I too am alarmed at the number of qualified referees who think the original decision was correct, the rationale seeming to be that her arm was in an unnatural position. Which is ridiculous as she was stretching for the ball, and as I've said countless times before you can't play football with your arms pinned by your side. I'd argue that anyone who thinks you can has never kicked a ball at any kind of competitive level.
I also agree that she had a very unconvincing game. The most baffling of which, penalty / non penalty aside, being when she ludicrously gave a handball against Jill Scott when she was looking straight at it and the ball was nowhere near her arms. However, she does deserve some credit for changing her mind as there are a lot of referees who would just carry on with the penalty regardless.
The problem she now has though, mainly thanks to English player interviews, is that the whole World thinks she changed her mind because of player complaints. I'm sure that isn't the case, and rather one of the other officials bailed her out, but she just didn't sell that at all well. Personally I think she should have gone to speak to whichever official gave her the information as that would have made it much more obvious that teamwork had come to the rescue rather than her having collapsed based on player complaints.