I googled the error and it seems that changing the password invalidated the access code, which means that I need to get a new access code and grant permissions and all that all over again.
Luckily I can do this by having her log in and I can just tweak everything from there, so it keeps everyone happy.
This should indeed be a simple “I need the password so please let me have it” issue, but it’s all just politics that I have to get around.
Thanks all for the help.