It does become difficult to always say YES to people asking for accommodation as we have requests from family and friends often re accommodation due to where we live... very handy to get into Central London etc. Family from overseas come in groups and for weeks!
We worked out that we had only 3 months guest-free 2 years ago So we started becoming a bit stricter for our own sanity, and our pocket
With childminding now it is nigh impossible to have guests for more than a week as the guestroom is now the playroom, and it's a schlep to have to rearrange furniture every morning, plus they have to be out real early too!
It's difficult saying no though and we rarely do.
Most people in our church are young families and have full homes pretty much, so not sure there is anyone, but worth networking!
I also asked her for the months and dates... as people might be away on holiday and would like a housesitter. She could then help out at the mums and tots groups etc during the week, great for learning English.