I think you've been given great advice above.
Fingers crossed that Poppy isn't pregnant, but if she is then make sure you separate them in a timely manner otherwise, as they are not averse to incest, you will end up with many more very young very pregnant hamsters, as well as fighting hamsters.
It's worth noting that Hamster Central has a rescue and rehoming board, which would also be a good place to advertise as it probably attracts a more knowledgeable readership than Gumtree!
http://www.hamstercentral.com/commun...nited-kingdom/