help, delicate money question: taking dd's friend on holiday

[Steamroller]

we have invited dd's best mate to come on holiday with us for a few days , we are staying in a cottage. Taking the other girl won't cost us anything because we've paid for the cottage anyway and she will have spare bed in dd's room. We won't be doing activities or at least not anything we have to pay for. If the girl's mum asks us if she can pay us anything, or just gives us some money, what should we do? A little extra would be welcome, but then again we don't want to seem money-grabbing . What SHOULD we do? I'd like to avoid an embarrassing scene with us saying 'oh no it's alright' and her saying 'oh yes I insist' and then if she does insist are we supposed to give in. or not? And then how much is right, and how much is too much?? Help!

We took a friend of DS's (teenager) on a self-catering holiday last year &, as neversaydie suggests, his parents paid for a meal out for all of us (& very nice it was too!) And they gave us some wine when we got back.

It did feel a bit bad taking it, as having the extra child along meant we all had a better time

I wouldn't expect anything but, as others have said, if I was sending one of my DC I would send them with pocket money, a reasonable contribution (£50?) to food and/or a food parcel (including wine!).

When I was a teenager a friends DM used to have a random collection of girls (including her 2) at her cottage in Wales every year. She used to ask for £30 per child + food parcel (cakes etc) - but then feeding teenagers is expensive (and she did have 8-9 in the (small) house at any given time!)