Shower thank you note after death?

Keep the thank you to a thank you. You can send a separate sympathy card. I had a similar situation...one of my parents' friends attended my bridal shower and gave us a check, and not a week later her son passed away (he was my age and I knew him) and I felt SO entirely conflicted what to say, but my mom had good advice: you don't want to connect the wedding to their loss. Let the wedding and its festivities be a light in an otherwise dark time, something they can hopefully look forward to. I left a message on his obituary site recognizing him and sharing my stories of him, and didn't say a WORD about his passing in my thank you note. I just said thank you profusely and we look so forward to celebrating and having a lovely time with them on the wedding. Bringing up the person passed will sour it a little.

Thanks for the advice everyone! I will send her a separate sympathy card, in addition to the thank you card.