Was it empty of squishy this morning - meaning it did it feel like it may have been a little boggy or doughy?
Now, this is my personal opinion - If you suspect she might have some crop issues, you may want to eliminate the oatmeal. I used to give mine oatmeal, but have since stopped. To me it's sort of like bread, they love it, but it's not that nutritional. I feel that it can also become gummy, so if you have a bird that is having problems, then I wouldn't give it.
We all read things, I don't know how much of this is true - we have to weigh each thing and see if it makes sense for us - here's something I ran across that I found interesting
https://the-chicken-chick.com/the-shocking-effect-of-oatmeal/