Default [Q] MMS Recieving

My mom just bought the AT&T Variant of the SGS5. I have a Tmo Galaxy Note 2 on 4.4.2 Using S5 features.
Heres the dilemma (pardon my ignorance on the issue)

I tried sending her an E-Postcard that my family took at a kiosk at The Linq in Las Vegas (it gives an option to email the e-postcard. I emailed the e-postcard to myself, saved it to my Note2 then text her the pic) anyway....
I asked her if she got the pic and she said she was given a link to the pic but when pressing the link it comes up with a blank web page.
Just wondering if there is a setting I need to have her change ao it wont happen anymore.

TIA