The Marauders created the Map to insult Snape only. (And to not get caught making trouble!)

All death eaters are in slytherin

No some are not @Realhhhk

Example: Peter Pettigrew.

Yep

And Cedric Diggory in a alt universe(in the cursed child)

Peter Peteigrew (I don’t know if I spelled his last name right) Was actually in Gryfindor, even though he ended up a death eater.

Lily was pregnant when she was killed.

Really?

^I don't think its been confirmed. Some people said that JKR revealed it but we don't have proof.

I know all of this..