Live CD for Grandma

My mother has been using the VTech Postbox email machine for a few years. Unfortunately the support for those devices went belly-up at the end of March, so she's left with a paperweight, and no way to send or receive email. I'm looking for a viable replacement.
It seems that a dirt-cheap laptop booting from a live CD, with the home directory on a USB drive, would be a cheap and reliable alternative. However I'd like the machine to boot up as an email machine, hiding from her all the ways she might "mess things up" (as much for her peace of mind as mine). I guess I could live with web-based email, though I'd much prefer a pop mail client with as much stuff hidden from her as possible.
Has something like this been done before? Any recommendations would be appreciated.
Alan
It seems that a dirt-cheap laptop booting from a live CD, with the home directory on a USB drive, would be a cheap and reliable alternative. However I'd like the machine to boot up as an email machine, hiding from her all the ways she might "mess things up" (as much for her peace of mind as mine). I guess I could live with web-based email, though I'd much prefer a pop mail client with as much stuff hidden from her as possible.
Has something like this been done before? Any recommendations would be appreciated.
Alan