If the seeds have not yet germinated I would put some plastic cling-film to retain moisture and prevent drought/drying out of the soil.
I think they do not need the full sunlight yet so it might be best to move them away from the heat and light of the window just until you return.
I agree that cat-sitters are not always good plant-sitters.
As I type this I am dog-sitting for 4 days.
