Thunderbird is email client software running on your computer. I suggest you contact the email provider for your options for access to her account.

Thank you, I'll do that.

The messages that were already downloaded into Thunderbird should still be there. If you are prompted to provide a master password, you can cancel it and view existing local data, but you won't be able to retrieve new messages or send messages.

Still nothing. Trying to look for Thunderbird support. Must be the way I'm searching that seem nothing is available.

Sent msg to ISP for assistance. Thank you

This forum is the Thunderbird support but Thunderbird has nothing to do with administering email passwords. As stated, you do not need a password to view any emails already downloaded to your computer.