Just a follow up: broody hen took to the surviving two chicks and has defended them against the others. When I went out to separate the mama to be from the babies and turn on the heat lamp the babies were chirping under her wings so I let it go. Thank you for your help.
Broody hen was sitting for what I thought was 3 weeks I did t really keep track. I put day olds under her but left the other eggs thinking she would realize they were duds. Well she didn't realize that so I removed the eggs and left the baby chicks. Next day two chicks were squashed under her...