(Sorry for the shameless self promotion ... If anyone thinks it's inappropriate, down vote me:) )
Looks like Mailpin (http://mailp.in) is what your mother needs.
Does she know how to send email? If yes, then she just sends a mail to p@mailp.in, and the mail she sends become a web page like this: http://mailp.in/c8cN1BEb
Thanks for your testing! We have fixed the script / meta tag strip problem. We keep improving our code base, making sure emails are rendered correctly on web pages. We won't use user data for anything else.
If you put your link to public places like hacker news, then google will find it.
If you simply create a post page and keep it to yourself or share in a closed social network (e.g., IM, facebook private group ...) that cannot be indexed by google, then you are good.
That said, you decide to what degree you want to share your page.
"I never got around to turning attachments on because I was afraid of the hosting costs; how do you plan on dealing with those?"
As long as users don't delete their posts, we keep them (including attachments) there. If we are running out of storage space, we can add more machines :)
Looks like Mailpin (http://mailp.in) is what your mother needs.
Does she know how to send email? If yes, then she just sends a mail to p@mailp.in, and the mail she sends become a web page like this: http://mailp.in/c8cN1BEb