If all the blood work looked good it means that the liver and
kidney functions should be normal since the liver and
kidney functions are usually checked when routine blood work is performed.
Have X-Rays been performed? These are usually done prior to having an ultrasound done. An ultrasound is not invasive and could give you some good information, however, it can be costly.
Have you tried giving her pepcid or zantac when she first gets up?