@CravenLestat Yes, it must be glitched in my game. I always send my sims to the cemetery at midnight, and they fish until they've caught six fish. Then the death fish disappears. But this time, the death fish never came at all. I know what it looks like when it comes, but I had her inspect it repeatedly anyway, and it really was not there.
I placed the wishing well on Pirate Island, on the same lot where I had placed the surfing wave station, so she could kill two birds with one stone. So I found out she can't fish with bait, which makes it useless. I had her master scuba diving before she started fishing, so she had already caught a lot of the "fishing" fish, but once she started fishing she had to catch them again anyway, by fishing with bait, because that is one of my goals for all sims I have doing the fishing skill.
She is ready to go to university. I don't remember for sure, but I think there is a graveyard somewhere there. If so, she's going to catch her death fish there. Hopefully, it won't be afflicted with the same glitch.