What do you suggest if my father has shingles can my 5 yr old daughter and newborn catch it?

Maybe/can avoid it. The shingles are reactivated chickenpox, but transmission is very different.Shingles is only passed by direct contact with the virus weeping from sores or in bandages. It is not airborne (like Cpx) nor is it in their saliva.Unvaccinated kids can get (unlikely at 4) it but your newborn is likely protected if you ever had it or the vaccine. Keeping both away from his sores is enough to avoid it.
Yes. Yes Shingles is reactivated chicken pox virus. Your children most certainly can catch it. Your 5 year old I hope has had the chicken pox vaccine but your newborn has not. Until lesions are crusted over your father should stay clear of any one immunocompromised or otherwise vulnerable. .