My great thanks to Fred for his original tutorial. I managed to get connected by following his very clear directions, with the appropriate modifications for my (wife's) computer, Finch.
Finch used to be an XP-only machine, but with the demise of XP support, I am migrating her to Linux Mint, which she enjoys.
Her Thunderbird email profile is still in a Windows partition, and I wanted her to be able to access all her mail in the same profile, no matter whether she boots to Windows or Linux.
My attempts at solving this issue, by pointing the Thunderbird "profiles.ini" file (in the Linux partition) to the Thunderbird profile in the Windows partition, worked up to a point, but I had to ask Linux to actually open the Windows partition each time she turned her computer on, otherwise Thunderbird could not find the Windows profile.
I did try Menu > Preferences > Disks > More Actions > Edit Mount Options > etc, etc., but it would NOT make the changes to the fstab file. I had to go in and change the fstab file manually.
I used Fred's tutorial and edited fstab successfully; and now Linux opens the Windows file system properly every time.
Thank you Fred.
In this world there are just two types of people. There are those who divide the world into two types of people, and there are those who don't.