Report cards & potty training

Emma had her 1st semester parent/teacher conference last Friday. She's doing really well in 1st grade. Her teacher grades on a 4 point scale (1-4), with 4 being the highest. Her teacher even prefaced the conference by saying she does NOT give out many 4's because then the child wouldn't need to be in 1st grade. Emma got mostly 3's, I'd saying 97%. She had a couple 2's in reading/language arts, but her teacher said she believed this to be from Emma's speech issues that we still struggle with. She also got a couple 4's in math (she takes after her dad in this). All in all, it was great. We see the areas where we need to give her a little more extra instruction, and we'll work on that. We also got her speech eval, and she's made great progress in that. She's probably at about 75% in meeting her goals from June.
And now the potty training. Not Emma, Sarah. Little Miss Sarah-Sarah has been having a problem lately with taking off her diaper at every opportunity. She hates having a wet diaper on. Of course, she also hates having clothes on, so it could be a pattern, but anyhow. I took the cue from her and put her on the potty seat one day, to see what she would do. She didn't do anything at that time, but the next 4 times I put her on, she went. She seems to be really proud of herself (as are we, and we cheer for her when she goes) so I think this may be the start of potty training for her. We didn't expect this so early (even Emma didn't start until after she was 3), but I'm not going to knock it. I know it's a long process (I don't see how my dad potty trained all 3 of my siblings in one weekend each), but if the end result is one less child in diapers, I'm all for it.