Disaster strikes the windowsill!

I'd just got up this morning and went to check on our little seedlings and two of the sunflowers appear to be completely wilted over! I don't know if this is because they've not had enough water or because they're getting too big for their seedling trays. I'm suspecting that it might be not enough water as they are two of the smaller sunflower shoots. Anyway, I've given them a good water this morning so hopefully they might perk up again. I did also yesterday invest in a whole load of pots and saucers so we can start repotting some of the bigger seedlings today.