As a bride to be I visited one of my favorite boards, The Knot, to see if the bride was a "knottie." It appears she was not, but I did find this posted by a bride who has a mutual friend of the couple:
"...I know a friend of the bride and groom. I work with her and she is beside herself about this. Both families are extremely upset about the situation. It really has not been good...And to clear things up: the couple had been up on the 10th deck - the top deck - the promenade, and she had went to bed without him. He had said he wanted to get something to eat before he turned in. The bride woke up in the morning and had initially thought he had gotten up earlier than her and hadn't wanted to disturb her so he went back to the casino or went to get something to eat. She went looking for him but couldn't find him and eventually went and found a steward. At about the same time, people who had cabins with balconies on the 8th and 4th decks reported finding blood on their balconies. They believe he either leaned too far over the railing and fell, was sitting on the railing and fell (which he had been doing while she was with him the previous night), or he hit it big in the casino after his bride went to bed and someone jumped him and pushed him overboard..."
I left out a portion to avoid the copyrighting issue.
I don't think it's unusual that they weren't together all night, especially if they had a drunken argument. I've had those with my fiance, and I'm sure we're not the only ones. They're young, just married high school sweethearts with high proof liqour on a vacation. Even thought it was their h-moon, that doesn't mean they had to be joined at the hip every second of the day.
I'm thinking drinking games could have been involved and Jennifer could have either passed out or blacked out the events of that night. The drinking games could have escalated into violence on the deck, particularly since they were drinking absynthe, it could have caused a strange reaction in everyone, or it could have been robbery.
In my heart I cannot assume the bride knew/saw anything and wouldn't want justice for her groom. I'm afraid she was passed out somewhere on the ship - NOT in someone's room - or blacked out drunk in the room and doesn't remember a thing. Just because witnesses said she was "flirting" (was she? a pretty outgoing confident girl who talks to members of the opposite sex isn't necessarily "flirting") isn't going to have me labeling her as an adulterer and her honeymoon, if she could barely stand and running into walls, chances are she wouldn't be able to muster up the effort to go cheat on her new husband...