Not really.
If you laughed while attending your mother's funeral, that implies very little. Not all funerals are sad events, even for loving people. Laughter isn't banished from moments of grief because it's not always inappropriate.
If you laughed BECAUSE your mother was dead, others may deduce that you're either heartless or had no emotional or physical connection to your mother which merely signals you as tactless or gauche.
Many
have found it morbid. It was neither relief or ridicule, and I'm sure if my family were full of SJs it would have been seen as horribly tactless. It wasn't toward my mother, with whom I was close, but basically making fun of the actual funeral (I fucking cannot stand funerals, weddings, or any other sort of traditional event, for the most part), how gaudy my cousin's hot pink dress was, and how bad the organ playing was.
While I'm plenty aware of laughter helping to heal the pain, it didn't feel like that was what I was doing, even if it did help. Seriously, the funeral was hilarious, and I find something farcical about open caskets and dead bodies wearing grotesque amounts of make-up. No, it was genuinely just hilarious to me; I'm starting to giggle remembering it.
There's also something amusing about how death is treated through all human cultures, but especially ours.
I don't know if it's related, but I'm going to will my skull to whoever wants it after I die. But that's not really humour-related, I just think it'd be pretty awesome.