Global sugar art has a damask stencil that is very close. It comes in a 4 or 5 tier set. If they dont have it in stock you can get them at designerstencils.com
Agree with Bfisher2, you want to work with stencils, fondant won't look as good
Definetely go with the stencil.
If you can't get ahold of a stencil in time, you might think about copying the picture, laying a piece of parchment over it, and tracing the pattern with royal icing. Let it dry overnight and then carefully peel it away from the paper and "glue" it to your cake.
Take a little more time, but it would work in a pinch.
hi i know i've said this before, but i do henna, you can go to the henna page, there is an area with free patterns, damask is used a lot in henna, scroll through the pages and it will show you many patterns and how you can enhance them. i would use the piping gel transfer method. she must want the background to, and really light like the invitation background, what i was talking about was the swirl, but you can also find a lot of the background looks, how big is the cake, you can enlarge the invitation, and try the same method, do you know anybody with a cricut. for a stencil, i'll will say i've never done anything like this, but a stencil i would think would be the only way to go for the background, there is so many different designs. and i'm not good at all with writing would she settle for join us in honoring the mothers name. just a thought