Mouse help!

CeCelia

So apparently we forgot to lock our doors last night and my cat went out on an early morning hunt (he knows how to open doors). He got ahold of a mama mouse and her child (we think). The mama is dead but the child is unharmed, however scared. We want to take care of it if we can. I got a fish tank for it and different kinds of food to see what it likes. But the water bottles they had at the store were so big and it will take 2 days for a smaller one to be shipped here. I put some water in an old contact lens case that I cleaned out. Do you think that will work? It's such a little mouse. Will I need to give it drops of water instead? It's definitely not a baby, but still looks young

It's at least a little happier since we put it in the tank. Was exploring a little before burrowing into the bedding