When mine was setting she got up on her own, but I've heard of others that lost the self-preservation instinct I guess.
I wouldn't worry about her getting off the nest as mine got off the nest everyday for several minutes. She even went out and pecked grass and bugs sometimes and I've got 8/9 eggs hatched to show for it (the last pipped, but didn't make it out). She will also need to get up periodically to "relieve herself" or else she'll spoil the nest and I'm sure that's not good for the eggs.
I wouldn't worry about her getting off the nest as mine got off the nest everyday for several minutes. She even went out and pecked grass and bugs sometimes and I've got 8/9 eggs hatched to show for it (the last pipped, but didn't make it out). She will also need to get up periodically to "relieve herself" or else she'll spoil the nest and I'm sure that's not good for the eggs.