Today we originally intended on doing some outside work at the house, but the wind came up and made the project inconvenient and even potentially dangerous, so Lisa decided to get the GFI installed.
Here's the finished product. After working out which circuit breaker covers the bathroom and shutting it down, Lisa spent some time working out by trial and error which was the first outlet in the circuit. (It's the one on the left.) That outlet is "upstream" of both the light fixture and the second outlet. By putting the GFI-equipped outlet upstream, it protects all of the outlets downstream from it.
Incidentally, the little indicator light showing that the circuit is live is also a gift from Christopher Carson. It is very handy.
I'm glad we finally got the master bathroom outlets protected like this.