FH and I are registered at Macy's. We have already received some wedding gifts. Since we don't live together - the gifts have been delivered to my parent's house. Every gift that we've received so far have been from my guest list. However, we got some towels from someone on FH's side. I don't know this person - it's a friend of his mom's. (FH barely knows her as well). What should I write for a thank you?