8U and 10U pitcher warm-up finishing what time before game start?

[Rotation 123]

Interested in opinions and or resources that deal with when the starting 8u and 10u pitcher should complete her warm-up compared to the game start?

 

[fastpitch]

I usually make sure they are finished with their warm up just 5-10 minutes before game start. I have no real reasons except it just seems to make sense they are warmed up and ready right before they have to pitch. Also each pitcher takes a different amount of time to warm up so you need to take that into account as well.