It's hard to tell from that position! I agree she could be a Welsummer, but when I see a broody I always think game hen, and they come in the same color.
She reminds me of my little dutch bantam i used to have. They look exactly alike. Yes, those are her babies that she hatched. 11 of them. (I'd go crazy with that many kids) they're mixed.
she is bigger than my dutch bantam BUT she isnt "beefy or meaty" like my Orpington. She has a slender well did have a slendeer body before she hatched her chicks