[LunaTheHamster1]

Umm, tricky one. On the one hand they are not being fully responsible in taking on a pet and all the responsibility that entails in that they can just give it back, but on the other hand at least they are wanting to try it before they commit.

If it worked out it could be a good thing, but if they decide to return it you have just put your hamster through one upheaval in getting used to a new home and then returning back to it's old home.

I know most rescues will let you adopt a hamster on the proviso that if anything ever happens and they need to rehome the hamster again that you have to take it back to the rescue and not just give it away/advertise it. But they wouldn't be expecting it to return in two weeks.

I think what would be best for the hamster and the people involved is to discuss what their expectations of having a hamster are and see if that matches up with what actually owning a hamster is like.
If you get it right in the first place then there should be no need for them to return a hamster.
What reasons would they expect to return the hamster to you??? if they have any doubts, maybe a hamster isn't the right pet for them.