LOL!

I think all that is pretty normal for the stage and age. Especially with the first child, I was trying to figure out what was normal based on what I saw other children doing. I'll bet most parents do that. After awhile we all kind of figure out what is normal for our own child.
I hope your SIL isn't stuck on comparing the two. That might end up being uncomfortable for everyone.
Our neighbor is an exceptionally gifted swimmer. The kid was just built to swim and she's very comitted, works very hard.
Both my girls are having a great time on swim team, this is our first year. If I expected them to swim like their neighbor, it might not have been such a fun experience. I'm proud of all three girls, they are each getting something a little different out of the experience.
For the record, I've found it just doesn't work to talk frankly with our close relatives about issues concerning the girls' intelligence and capabilities. It just doesn't end well.