Stolen iPhone 7 Product RED (Can't recover photos)

Hello,

I have a problem, my younger sister had an iPhone 7 Product RED as you can see in the title. It was stolen in August in shoe shop called Deichmann. Some b**** woman stoled it (sorry but how else can I call a person who just stoles phone to a child (please don't say that kids shouldn't have iPhone or such things, but she is very responsible and this could happen to anyone). We actually couldn't track it trough Find My iPhone app, because the woman she turned the phone off, and didn't turn it on (my sister have 4G data also so we could track the mobile if it was on). Now my sister ended up with a new red iPhone, but here is the problem, we wanted to recover her backup from iCloud, which she had turned on on the first phone, but when we did it we couldn't find the photos there (she had over 8000 photos....and it was alot of memories). I just want to ask if some of you would know, why she hasn't got the photos on her new mobile? The backup was same as it was: settings, apps, ringtone, wallpapers, songs, accounts, everything, but photos not. Could someone help us? Do you think that we can get the photos back?

I appreciate any help

Thanks

Marko