I would agree with you Eliza, but from prodding her stomach and many other things, i can tell you there is a small chance those are eggs. Since she was about 7 months she has at random times gotten those. I think it's just fat pushing with indents of ribs.
However, she is due for a vet checkup this month so she will be getting x-rays for post ovarian eggs.
And this is a picture from almost a year ago, same thing, however in the picture up top, she is sitting up so her belly is more pushed out on the bottom.