Your client needs an email application capable of opening html files (which
she may or may not have). Outlook/Outlook Express are just two of many that
would do this, but even then you have to have the "HTML format" option
turned on, as opposed to plain text (which is a user option - tell her this
and she may find she can open it after all). The best thing would be to
just email her the link to the web page rather than try and intergrate the
webpage in the email, since you run into problems as you obviously have.
Your client won't need Frontpage.
Also, you will need to host all the pictures etc on a web server with
absolute URLS as they won't be integrated in the page or saved and sent in
the email.