Can I change an account password in Movable Type?

I used to think that this wasn't possible, actually, but in fact while there's no way you can set her password to something you specify, there is a way that you can reset her password and give her the opportunity to log in and change it to something she prefers. I would encourage you to have her run an antispyware check first, however, to ensure there's no problem with keyloggers or similar.

Here's how you reset her password in movable Type:

First, log in to the MT backend using your administrative account information. On the very top you'll see this:

Click on MAIN MENU and you'll get a summary view of all your blogs and, on the right, a list of convenient shortcuts:

Click on AUTHORS, as you would expect, and now you'll see a list of all the authors you have registered within this copy of MT:

(I blank some of the information out on these screenshots for security reasons, btw)

Scroll down as needed to find the author's account, then click on the account name. Now you'll see an author profile page like this:

A critically important thing to check here is do you have the correct email address registered for this author? If not, now's the time to update it because their new password is sent via email.

Scroll down just a bit further and you'll see:

That's what you want. Click on "Password Recovery' and it'll remind you with;

If you're sure, click "OK" and you'll get a confirmation message on screen:

More importantly, your author will get an email message that gives them a new temporary password and details on how they can change their password to something they prefer.

that should get your author up and running again!