Kitty meowing a lot at night?

Hi. Yesterday my family got a kitty. Because her owners are going on vacation. They told us how to take care of her, and we followed the instructions . But at night she kept on " meowing" , we think that she's hungry, but the food and water are already provided like her owners told us. ( we have her litter if you're wondering ) So today we went check on her but see that she didn't eat, or do anything 'cept went in the litter and did her business. We all understand how kitties get scared when they move to a new place. But we wanna make sure therw aren't anything else causing her to meow that much in the night. Thanks!