Refurbishing

I'm currently working on a diorama project for my ¼ sized dolls. Since they are mainly girls ... and also girls who love girly stuff, we decided, that they are going to get a shabby chic styled living room on the middle shelf of my cabinet.
Everything will be kept in white with accents in pastel colors and lots of roses.

We started working with the couch. This is what the couch looked like 3 weeks ago:

This is what the couch looked like after almost 3 hours of taking it apart:

This is what it looked like after the first coat of white color and with the new upholstery:

I told you, I'll be going for white and motives with roses. Cliché-y much? Yes, but also cute xD. Which leads us to what the couch looks like right now:

Already looking good, isn't it? I still need to add a decorative ribbon around the upholstery, similar to what the original design had, so that it'll look more nicely, but I still did not get around doing this. 

Honestly, I have no clue what to use to make it work. Simply just glue and stick it on? Or should I go the whole way and sew it on? Decisions, decisions. Anyway, the girls can already sit on it, so I can take my sweet time with the finishing touches. ;)