Why your girl is in the hospital? why the hospital check your milk?
When my by was born and he was checked with very "yellow", he stayed at the hospital also. The nurse just said that they would not transfer my expressed breast milk into their bottle for feeding him as they would try not to move the milk as far as possible in order to lower the risk of having bacteria.
Also, all your milk must be chilled when you transport the milk from home to the hospital, e.g. use a fridge to to, such that the temperature of the milk could be kept low. In fact, breast milk after expressed out could stand alone at room temperature for around 6 hours without problem.