re: Daughters First Deer Hunt - How early is too early?

Unless you have a 120yd pin I doubt you have to worry about shooting one in front of a 5yr old.
I would wait till gun season and bring her if she wants. Both of my kids started shooting guns 4-5 and being around dead animals when they were in diapers so it was not a shock for them to see the first one dead.
Just make it fun and let her look through binos take pictures of other animals and don’t harp on being motionless quite and stuff or it will burn her out quick.