It's like christmas- More bantams coming! ???s

[lady feathers]

Tomarrow I am going to meet up with a lady who had posted two brown bantam chicks on cragslist, she doesn't know what type they are but they are only 4 weeks old. Same age as some silkies we have n the brooder. She found out they were going to be part of my 2 1/2 year old daughter's own mini flock and said she would give them to us free! It feels like Christmas, we know we are getting a present we just don't know what kind!

How long do I have to quarantine these two from our others chicks.... if at all? They have been in a brooder too not hatched by momma! Also, how far from my other chicks would they need to be? Thanks!