I stumbled across some really cool apps a couple of months ago, such as Photobook. It is so cheap and easy to make a nice little book of your own photos which your wife will cherish.
They offer free 20 page books and you can select how many images you have per page. There are other apps which offer even more for free. They do charge above average postage, which is where they cover their costs, plus they have extras like making it hardback, which is where they make their money.
This is an amazing gift as you will need to put a bit of time into it- it can take ages. It is sped up by allowing you to choose photos from your social accounts like Flickr and Facebook and I assume Instagram.
I use the iOS app but thy also have it on Android. Check a few out. Another option which might be a good Christmas present, not just for your wife, is a personalized calendar for 2018.