I also had a girl with sour crop a few weeks ago. I did not vomit her, although she spit up on her own while massaging her crop.
My girl moved her neck around like a snake, thats how I knew soething was wrong. I'm guessing everything got jammed up form a clump of grass she inhaled (stupid of me to throw it in the run in the first place) needless to say, I have learned my lesson.
I seperated her into a dog crate and withheld food for 24 hours. (good way to do to determine if it is infact sour crop) Feel it in the morning. Hers felt like a tennis ball sized water balloon, very squishy.
I had acv water available at all times and on the 2nd day tried to feed yogurt to get those good bacteria back into her. Alas, she would not touch it so I added probiotic capsules into some warm mash I made with warm water and layer crumbles. I also had to force her to drink the acv water by dripping it on her beak.
Everyday i would massage her and in a little over a week all was well. I think it took a little longer because I was not comfortable "vomiting" her. Just be patient. Curious to try those pills Chris09 mentioned. Seems like something good to have on hand.
Let us know how she does.