This guide offers tips for writing acknowledgement letters to families for donations made in memory of a loved one. What do you need to include in your donation acknowledgment letter?Remember to include gift details, such as gift date and gift amount, in your acknowledgment letter to the donor. 3. This guide will cover everything from nonprofit memorial donation thank you letters to keeping track of memorial donations and how to notify families. Does anyone have an example of an acknowledgment letter for "in honor of" and "in memory of" donations they'd be willing to share? 1. Personalize the message. Just like any well-written donor thank you letter, your memorial donation gratitude notes should be personalized to each donor.