Dear LFTP: thank-you note after a goodbye tea

• Is a thank-you note proper after a dying friend's goodbye tea, and who should receive it?

A host reads a letter from someone invited at the last minute to a dying friend's 'goodbye tea' hosted by the friend's four children, asking whether a thank-you note is proper and who should receive it. The hosts advise sending the note to the children who organized the event, and read the 'secular' answer suggesting a separate note to the friend herself expressing gratitude for the time together.