I believe the man's widow attended, but it would have been most improper for Hamilton to have received an invitation. Indeed, near two-dozen admirals refused their invitations, so much did they disapprove of Nelson's scandalous private life.
Personally, I think they judged him too harshly and did him a disservice. I met him once, briefly, and shortly before his glorious death. I was most impressed by him, and I mourn his loss to the nation.