Cheryl you are doing great.....If you feel she needs extra help, you might consider vitamin water. Remember that she's concentrating on those eggs but yes, she must get off the nest for food water and evacuation!
When I had a broody once, all the other hens went in her area went broody....Watch out this could be contagious....Especially if they see all the TLC you're giving her....
Oh and one more thing.....follow your instincts with her....but mainly don't disturb her too many times.....Sounds like she's a dedicated mommie!