Slightly larger stomach - anything to be worried about?

Hi all,

This is Beau! She’s 2 next month and she’s suddenly developed a bit of a larger stomach, which we’re slightly confused about.

For context, Beau lives with Brian (he’s in the last picture; he’s 2 tomorrow!). Beau isn’t spayed and Brian isn’t done either, but she came out of heat in late March so we’re convinced it’s not a pregnancy.

Beau hasn’t changed her behaviour at all and is still eating, drinking, and digging to her heart’s content (but she does have to eat away from Brian now as they had a fight over a treat-burger about a month ago!); however, she’s never had a stomach this big. My vet friend said I should try and see if she can express milk ( which she doesn’t) and she hasn’t had any discharge or puss form her vagina so I think we’re clear of pregnancy.

We’re keeping an eye on Beau over the next few days but we’re thinking about taking her to the vets if she changes her behaviour at all, but I wanted to know if anyone in the community has experienced anything like this? Is it normal at all?

Thanks in advance for any information you can provide.