I was making an appt for a senior relative whose last name is similar to mine, but is off by one letter. In my mad rush to finalize, I didn’t realize that I put my last name instead of hers. Will this cause a problem? It’s one letter, and I don’t even think anyone will notice, but wondering if this will cause unnecessary trouble. She’s in her mid 80s and recently went through chemo, so a bit worried.

I don't think so. I made appointments for my parents and hey had to complete supplemental nys health forms so I assume she can write it correctly there?