I only have 1 light brahma hen who has only gone broody twice in 4 years. She never got the opportunity to raise a clutch yet. I have heard they are great mothers but have no experience with it myself as of yet.
I had 4 buff orpingtions hens for Several years. Only had one of 4 go broody. But she would try and go 3-4 times a year. Her nickname was Mrs Broody. I never let her raise her own chicks. We just had to many snakes around for that.