We just received a gift (a check) from a friend who was not invited to our upcoming wedding. I feel somewhat bad as she invited both of us to her wedding last year and we attended. This came a few days after the thank-you from her baby shower (I didn't attend, but sent a gift) in which she asked when the big day was coming up, so I'm not sure if she expected to be invited.
We decided not to include her because (1) we're not terribly close, I was somewhat surprised to receive her wedding and shower invites; (2) we've had almost no contact since her wedding last year; and (3) we're keeping our wedding very small (we're expecting around 70; hers was about 300 people).
I know I need to get a thank you out straight away -- is it appropriate/necessary to mention something about the wedding? Apologize, explain we are having a very small wedding, something along those lines? Or can I avoid mentioning the issue?
ETA: Her due date is also within a week of the wedding, and she would have to travel a long distance, so we thought probably she wouldn't be able to attend anyway, but it's hard to know...