Parents: at what age is it inappropriate for children to come in to your bedroom and get in bed with you in the middle of the night?

Parents: at what age is it inappropriate for children to come in to your bedroom and get in bed with you in the middle of the night?
This question is NOT at what age your child should stop sharing your bed routinely. I am asking about those nights when a child comes into your room and says they are scared, can't sleep, whatever excuse, and they want to get in bed with you.

This issue arose in a private conversation recently and I had no context for understanding since I have never had children. If you are a single parent, does the answer depend on whether the child is your gender or opposite gender?
I don't have kids
Vote A
There is no age at which I would send them back to their own bedroom.
Vote B
They shouldn't be in my bed once they are approaching puberty
Vote C
Probably should be sent back to their bedroom at age 11-12
Vote D
Probably should be sent back to their bedroom at age 9-10
Vote E
Probably should be sent back to their bedroom at age 7-8
Vote F
Probably should be sent back to their bedroom at age 5-6
Vote G
Select age and gender to cast your vote:
GirlGuy
Parents: at what age is it inappropriate for children to come in to your bedroom and get in bed with you in the middle of the night?
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