I keep in touch with the owners of 4 of Blues litter mates.
Blue has one sister with the same coloring and face. They're almost twins and they look like the dam.
The other 3 look nothing like them, but they do look like each other, and the sire.
It's very common.
Also, female bulldogs are usually "softer" than the males. Their heads can be smaller, and their bodies "curvier".