@Jess76
Difficult Jess, how well do you get on with the neighbours above? Is it possible you could have a word with them and see if they can control the foot noise a bit! Perhaps put in a floor rug or two in the main traffic areas
You are right, it is going to be an issue, not too many guests are going to be comfortable, particularly if there are young kids involved upstairs! They seem to create 5 times as much noise as adults.
You have to be really upfront about it, much like owning a dog....you need to be sure potential guests are aware of the situation because they will want to cancel and get a refund if it is sprung on them!
I am sorry I can't offer any concrete suggestions short of creating more of an insulated barrier, and that may not be practical. There is a 12mm sound absorbing foam on the market here in Australia which I am sure would be available in the UK. It is designed for sound recording studios and it may be possible to install that to the underside of the guest bedroom ceiling. With battening and painting you could end up with a reasonable textured finish that would not be unpleasant to look at.
My listing is at the other end of the scale! The building being tripple skinned and with two layers of ceiling and insulation, one guest said it is so quiet in the cottage he could hear his heartbeat. When I asked he assured me he wasn't having a heart attack!!
Sorry I can't be of much more help Jess....best of luck with it!
Cheers.....Rob