My daughter recently got married and I invited the other professionals in my office. My daughter informed me that she did not receive a gift from one of the persons, although the person and spouse attended the reception. Should I assume that they didn't bring a present and say nothing, or should I mention to the guest that my daughter was sending out all her "Thank you" notes and hadn't received a gift from them. My daughter is concerned that the gift may have been lost and she doesn't want to seem like the bad person if they truly brought a gift and then don't receive a thank you note.
No, it would not be appropriate to assume the person gave a gift. I understand your daughter's apprehension completely about the thank you note though. However, the best way to deal with this, I think, would be to try to find out about the gift covertly.
Perhaps during a conversation about the wedding you could mention about all of the wonderful gifts, the thank you cards your daughter is writing, and "jeez, there was no card attached to one of the gifts (or something like this)." Perhaps your coworker will give you some information about her gift if there was one.