Is this definitely a girl?

[Vectis Hamstery]

Sorry - I must have misread it as one pic of each of your hams!

Male bulges usually aren't subtle unless they are very young (3-6 weeks old). There are some pics here (including my ham with undescended testicles). Have a little look at the pics of the female and you may see the same 'slight bulge' you describe on those

[AbiJ]

I think they were bought by original owner in March, we got them on 10th June which was about 6 wks ago, not sure how old they would've been when they left the pet shop? Those boys are very obviously boys though!!

[souffle]

If the other pics were both the same hammy then we better see some underneath pics of this one too. They may have been very young and the testicles not yet down or undescended as happens occasionally.

[AbiJ]

They are separated now anyway Souffle so not a problem either way, I've had a look and I think the other one is a girl.