Congratulations!!! What does she like? I would say something to keep that she can look back at in 20 years or more and remember the trip. Maybe something from the Art of
Disney store or similar to the things they carry there- I think they still have the store in EPCOT but it moved to a different location- there is one at Disney Springs too. Arribas Brothers has some good keepsakes too. I have a really little etched Mickey paperweight from my first WDW trip with DH- our Honeymoon-- takes me right back to that trip. I also have a little Swarovski Cruella limited edition crystal paperweight that was bought on Ebay in the last few years-- I fell in love with it on our Honeymoon, but at that time it was too expensive (we got the MUCH cheaper little Mickey one at some point on that trip instead). When I look at the Cruella one, even though I got it YEARS later, I still go right back to DH and I standing in the Arribas brothers store in Germany in EPCOT looking at it and him telling me to go ahead and buy it although I didn't. There is also a Jack Skellington figurine in our house that I liked on one trip a few years ago and didn't buy and my husband snuck back to the store and bought it and shipped it home and gave it to me for Christmas. Those are 3 things that I look at and immediately get happy trip feelings and a flood of trip memories. My DD has a little Olszewski gallery of light box from the Art of Disney store that she loves. I would say just something special that you can sit somewhere in your home as a reminder of the trip.
You mentioned Memory Maker--- they usually have some nice frames at WDW. You could buy a frame and then print a photo there and give her the framed photo of the two of you-- or even just print a memory maker photo when you get home for the frame.
You could get her a necklace or watch (if she wears watches)-- they have some pretty ones for around $100-- but I tend to get most sentimental about the couple of special things that sit on a shelf that I see every day.
There are so many different things. I would just keep an eye out for something she likes- or something with her favorite character, etc. I would just make it something that lasts- doesn't have to be overly expensive-- could be a mug, or Christmas ornament (for your first Christmas as a married couple), or measuring cups or spoons. Not something that will wear out or she will get tired of like a shirt, dress, purse etc.... unless of course she falls in love with one of those!