Waking up in the middle of the Night

Can anyone give me an idea of how you handle late night "wake ups?" If it were my own child, I would let the cuddle for a minute before putting them back in bed, but with the foster care side of it, is there another way to handle her begging me to hold her at 3 in the morning? I have avoided having her in bed like the plague, but she's wetting the bed and scared in the middle of the night.