They never peck her. I'm also worried about her feeling lonely.Do you have a small aligning pen? So during the day she can be with the other birds without getting pecked?
And at night you could sort something out, either indoors or in another shed.
I have had lone birds, but the mother rejected pretty late.
I usually use a broody. The chicks will be out all day, without going under their mother, after the first week or so.
I was worrying about my 6 week old brooder chicks.... But with the hen they're out all the time anyway.
They're definitely hardier than we give them credit for.
I'm more worried that she'll be lonely.