Stolen iPhone - problems with iCloud on iPod touch?

My iPhone was stolen a few days ago, and I'm now using my sisters iPod touch as a temporary replacement. In an attempt to get my photos back, I logged into iCloud on her iPod touch hoping they would show up in photo stream... Which they did for a second and then disappeared. Now when I log into iCloud on safari, the only photos which show up under my iCloud account are the photos she had already taken on her iPod, as if they have replaced all of the ones connected to my account. The thing about this is that she only has 50 photos, and Apple emailed me yesterday telling me my iCloud storage is pretty much full, which suggests the photos I originally had backed up to iCloud on my iPhone are still around somewhere.

Is there any way I can fix this to recover my files?

Thanks.