Mother of the groom

My son is getting married later this year. I get on well with his fiancee. However I feel excluded from things to do with the wedding. There was a big weekend when she went dress shopping with her friends and then again to make the final choice. She then took her mother along to see the dress and again for the second fitting. There were pictures on FB of them celebrating with fizz and generally being happy. I asked her what the dress was like and if I could see it but she said no. She wants me to see it on the day. To a level I understand this but it makes me feel I'm being treated like just another guest. And it probably sounds childish but I wanted to feel a bit more special. Do I say nothing? Or how do I tackle this?