great advice! yes. Some mommas simply dont care i find, some seem to just give up on the chicks, raising them for broody instincts, though this one sounds very loyal to the babies! We tried the brooder first for ours. They got a plentiful size i think, with lots of toys and little things to play about on, and got to go outside supervised aswell.I would leave the chicks with mom. It could actually be good for them to be exposed, so they can get immunity at a young age. Chicks are fragile, but also have young immune systems. Fowl pox isn't fatal, and if they get it once, they will never get it again.
Plus what @NatJ said, if the mosquitoes can still get to the chicks, they are hardly less protected in the garage than in with mom.
Mom will do a much better job warming them, protecting them, and raising them naturally than a brooder will. Could you imagine being stuck in a box your whole young hood, and than suddenly placed in this huge world with tons of big chickens around.
I've raised chicks both ways, and the only place I came out with all surviving chicks was with a hen.
I wouldn't bring them in. After all, momma sat on the nest loyally for 21 days, she loves those babies very much, she did ALL the hard hard work. Restricting her feed, all that time and energy, how is it fare to just take them away? Just my opinion.