leased to a family of four, now they want to add 2

[Diane Stinebaugh]

My first little ranch house.  three bedroom and one bath.  I leased to a family of 4 and now they want to have 2 more children stay with them over the summer.  suggestions? of course they could have 2 kids stay there and I would never know it. I live 15 minutes away.  Should I require an extra deposit?  $50 a kid?  I just think more people mean more wear and tear on the house.  It was built in 1964.

what do you think?