Well, except for the one homicidal parrtidge silkie hen, all mine have been very good mothers--free range included.
I've never had ANY hen lose a baby, although I have a friend who has "banties" (read that as mix breed very small chickens) who lose their chicks all the time.
In general, mixed breeds are better than purebreds at broodying--both setting and raising babies.
With all breeds, including the mixes, there are exceptions. I no longer let my partridge silkie hens raise babies because one of them kills the babies as they hatch--after having been broody on...