It wasn't until some time ago that I knew people used copies of the same character, but it does kinda make sense. This way, you're not running all over the place one just one charrie, nu?
I've even known one player who had different species-versions of the same character. Her wolf in my old roleplay, Hyacinth, apparently also had a hyena version, as well. (Sadly, sweet little hyena-Hya was killed by lions. </3)
But, as Rami said above, giving out one's password is just plain irresponsible, and she very could've lost the account if she gave it to the wrong person. When that does happen, though, I believe it's best to not even open their account on your computer, in case they decide to go and get themselves banned one day, and your IP address would/wouldn't be connected to theirs depending on that moment. Then, just explain how it's a bad idea to do that.
Granted, like you said, it was a long time ago, so that particular instance isn't too much to worry about.
(Still a kindacrazy floof, though.)