However did you get into this mess?
I think I know.
You just "reinstalled".
Then you added the users caitlin
and amanda in the reverse order
from your previous install.
So their UIDs (incremented by one as you add each user) are reversed.
User names are mapped from the (numerical) UID.
So they are back-to front.
"Dad" is OK as he added himself first.
If you haven't changed anything yet, you can fix all this up just by editing /etc/passwd
Hope I'm not too late with this advice.