introducing 5 wk old chicks to one broody hen

[LithiumPyrite]

Turns out one of our two hens was a rooster. . . So our friend and local hatchery offered to trade him for two 5 week old chicks. So we did. We only wanted one since it's just me and my wife but she said you want at least 2 to be buddies during introduction. So now we have one 9 month old and VERY broody orpington alone in her coop and two 5 week olds in a box in the garage.
Now I know that if I were getting adult birds that I would have to quarantine them for 30+ days before introducing them but since these are 5 weekers and still chicks is that necessary?
I kind of feel like I should quarantine them still just to be safe. If I do that they will be 9 weekers when I introduce them to Ms. Broody. I doubt the old switcheroo trick will work, meaning I don't think she will be fooled into playing mama with chicks that old. What do you think?
I don't want to get Ms. Broody sick or the chicks but I would like to introduce them as soon as possible to give her company in the now empty coop. Any advice would be greatly appreciated. THANKS

 

[TaylorHobbyFarms]

My opinion is also that it is too late to try the old switcheroo and introduce the chicks to the broody hen. For the most part, it is best not to add chicks to a new flock until the younger ones are at least 5 months old.