2(Supernatural)

An Au where Castiel took over Jimmy's body much sooner then in canon and that Amelia and Claire knew about it.

So, explanation on how this came to be: Jimmy had been in accident while Amelia was pregnant with Claire and while he woke up, he was bond to bed and that he might suddenly die as the accident had been pretty bad. Amelia and Jimmy were very broken over this especially as at any moment their daughter would be born and Amelia wouldn't be able to take care of both Jimmy and Claire(they have no other family) so their only option was praying for a miracle. Castiel heard the prayer and appeared in Jimmy's dream and explained his options to which Jimmy said he wished to talk with his wife and Castiel let wake up and waited. Amelia at first didn't believe that an angel had talked with Jimmy but at the end she did and they both agreed to let Castiel take Jimmy as his vessel as long as Jimmy was able to live and be normal for a few years before he left this world.

And that was what happened, Jimmy miraculously got healed and soon Claire was born. Both showered their daughter in love and Jimmy taught about being human to Castiel when he visited him in his dreams till the time Claire turned five and Castiel couldn't keep Jimmy alive longer without consequences so Jimmy said his goodbyes to his wife and daughter that passed away in his sleep.

Amelia knew that her husband was gone but decided to treat Castiel as a friend and help him more in how to behave as human but she found herself learning to love him(platonically) as she watched him trying to be a good parent to Claire which didn't change when they told the truth to Claire when she was 10.

How would this affect canon? Castiel wouldn't believe that the apocalypse was the best choice or that the angels knew better, the arc with Amelia and Claire would be different as he wouldn't completely abandon them and would make sure they were protected, Castiel would act more like a human and understand feelings better, etc.

Anything else, including ships, is up to the writer.