Haha, it's rare to have such a tutor who has such a good relationship with his students~ It shows that he must be a good person~~ Here are some tips for you:
1 Marriage is a lifelong event for women. Now there are special customized wedding doll gifts on the Internet. Ask her for a wedding photo and customize it online. I recommend you to have a look. It's a good choice.
2 Give her a music box. You can customize it online. Use a photo of her and her husband to customize a photo-customized crystal music box. The effect may be better than the ready-made ones in boutiques~~
3 Can you embroider cross-stitch? As a wedding gift, you have a good relationship with her, so it's best to do it yourself. You can embroider a wedding pattern or a photo of the two of them, and then add some tricks and frame it. It's very grand and thoughtful. She will definitely be very touched.