I had this happen to me too! Although she didn't directly ask me, she was talking about being a bridesmaid with other friends. I didn't want to hurt her feelings, so I took her out to dinner one night and shared a lot of the details of the wedding. I brought up the wedding party and explained that since it was a DW we had to keep the bridal party very small. I told her who was going to be in the wedding party and that if we were having a regular sized wedding and were having more attendants I would have loved for her to be included. I think being honest and addressing it right away helped relieve the awkwardness and everything has been great since. I also chose a few fun things for her to share with me during the wedding planning, such as a dress fitting and shopping for specific DIY items. This helped her to feel included.