We're going away - she is coming with us for a few days, then returning home. She'll be in the house on her own for five nights. There's plenty of food in the cupboard and freezer, but there won't be anything fresh, so I want to leave her some money to buy milk, veg etc. What's reasonable, do you think? I was thinking £30 - she's obviously more than welcome to help herself to anything that's already in the house, and I will do a big shop on the day we get home.