Sim will not age or die with family

Hello,

I have a sim that refuses to age or die. I turned on aging and the three other sims on the lot all aged and died (Including her husband.) This sim didn't budge an inch on her age meter and will NOT die. I've tried all the death cheats I could find. She's currently both mortified and hysterical and has been for days. I tried drowning her in the pool, she swam and swam for a damn week. Everything, and I mean everything is in the red. She should be dead three times over at least!

I tried moving in a new sim and blocked them both in a room with a grill. The room burned to the ground around this woman, killed the other sim, and she STOOD THERE SINGING HAPPY SONGS TO HERSELF THE WHOLE TIME! What??? My last and final attempt before coming here was having a vampire sim turn her, then deleting the house and leaving her in the middle of the empty lot ALL DAY in the sun and the damn woman STILL WON'T DIE!! I don't get it!

I've also tried downloading the mod for meeting the Nanny since I read somewhere that it should help. It didn't do squat for this crazy lady. I also do NOT want to delete her because she's part of a legacy family I've been working on for over a year. Since her husband is already dead I can't replace her with someone else and try branching the family another way. I just want her to DIE!

Help!