Oh no. 

Does her breath smell sour at all?
I don't think the oil is necessary, since that's usually used to treat impacted crop. When you're massaging her crop, I think you're supposed to go in a slightly upward, circular motion.
Personally, I've always fed them a scrambled eggs and a little bit of yogurt when that happens to my girls, but I've seen a few people say you shouldn't feed them anything. 

 I've never had issues from feeding them (as long as you're not force feeding them), but it's something to consider.
I'd recommend taking a look at the articles. I found a few of them that seem helpful. If you want me to link them let me know. I hope your girl feels better soon!
I love your daughters costume!