While reading an article, I came across this sentence (the article is describing people's reaction to a movie):
A young girl said, "I started crying. It was amazing."
I was under the impression that the ます形＋そう is used to guess or describe based on appearance and is usually translated as "seems" or "looks". It seems odd to me that someone would describe herself as having a "crying" appearance rather than simply stating that she was crying. Is this a different usage of そう that I am unfamiliar with? Is she perhaps stating that she actually did not cry and only looked like she was about to?
Finally, just to solidify my understanding, would the meaning change significantly if instead of 泣きそうになりました she said something like 泣きました or 泣いてしまいました?