there is no new vitamin or food change to explain
any upper right quadrant pain, has she been ingesting any blue colored drinks foods or dyes , any pain in any part of abdomen, fever, or constipation?
it could be salmonella, or she could have a case cholecystitis, or cholelithiasis(gallbladder disorders) how old is she, what does she eat, is she overwheight, underwheight, what does she eat a lot of, did she eat any abnormal foods the day before it started happening
I had the same mystery 28 years ago with my toddler... it turned out to be the grape juice he was drinking too much of.