Not surprised that you're RIR is laying first. In my flock, my RIR lays the biggest eggs and lays the most often. Hard to beat a Red. My next flock will be nothing but Reds.
Don't be discouraged when your first egg is small. It will be about half the size of the ones you'll get a couple weeks after they start laying.
Don't be discouraged when your first egg is small. It will be about half the size of the ones you'll get a couple weeks after they start laying.