PC to MAC Word conversion/formatting

I have a client who wants me to copy a typewritten manuscript. I'll be using a Windows 7 machine with Word 2000. We will want to open the file on her machine, which is a Mac
OSX v10.8.5 using Word 2000. So far she's been able to open emailed samples but the formatting is askew. If I provide her with a pristine CD copy (or thumb drive or small HD)
of the manuscript, will these same format problems arise? How do I correct them, if so? Or am I up s..t creek?

Thanks

Art

LibreOffice handles that type of problem for me.
http://www.libreoffice.org/