Well see, if Verizon gives you access to the nameservers on the domain there is no need for such rubbish. Are they going to be the ones hosting the DNS? If so I would transfer the domain out immediately because as a domain owner you want full DNS control not Verizon.

InstaPro.net allows you to transfer the Domain for $9.00 and comes with a one year renewal.

Then you just point the nameservers to your nameservers and everything works like normal.

i guess I'd need to know the whole reason that Verizon is telling her to use their MX. Are they providing specialty email services?

The MX can be setup in different ways and in most cases is not needed to be changed, so more info from you is required.