Pass it on
There is a kind of laughter that is not avoidance; it is recognition. The sudden break into joy when you realize the weight you were carrying was not yours to carry permanently. Joy is not the absence of knowing. It is knowing and being held anyway.
Sarah laughed when God told her she would have a child at ninety. The text does not present this as a sin. It presents it as a very human response to the collision of promise and impossibility. And God does not rebuke her; He names the child Isaac, which means "he laughs." The laughter becomes the name. The doubt becomes the memorial. This is not the laughter of mockery. It is the laughter of someone who has just been told that the rules she thought governed the universe are not as fixed as she believed.
There is a kind of joy that only becomes possible on the far side of despair. Not the shallow happiness of ignorance; the person who is happy because they do not know how bad things are. But the deep joy of the person who knows exactly how bad things are and has discovered, against all expectation, that the badness is not the final word. This joy is not a feeling. It is a theological position. It says: I have seen the worst, and the worst is not stronger than God. I have carried the weight, and the weight is not mine to carry forever.
The laughter that comes from this place is not disrespectful. It is the most honest response available to finite creatures who have been told that death does not win, that the tomb is empty, that the weight they have been carrying was never supposed to be on their shoulders. When you laugh at a funeral; the right kind of funeral, the kind where you are not laughing at the grief but through it; you are not in denial. You are in Easter.