if your ducks look different then maybe you can tell which one laid the egg...as far as chick breeds idk, do look like ee coloring though, sexing them is a bit early try posting when they around 6 weeks
If I remember correctly, Runner ducks lay tinted eggs that are about the size of chicken eggs.
On the chicks, I'm seeing a lot of EE influence on them too. Lots of green legs and puffy cheeks. I would expect to see some leg feathering if your Brahma was the sire.
That little Quacker is definitely INDIGNANT all the time! He goes off runnin around the brooder and quackin his fool head off every time I walk by. With my baby chicks I had been keeping them in my brooder for two weeks starting out at 98 and steppin down about a degree a day then movin them to my barn in an open cage with a heat lamp on one end for another two weeks before goin outside, should I do the same with my indignant quacker?