They will usually all hatch within 3-4 days of each other. Might take 24-48 hours to come out of the egg - no big rush - there's a huge yolk sac under the plastron that is much safer while the turtle is inside the egg, than out. It might a take 24-48 hours for the yolk to be absorbed. After the first crack in the egg I usually carefully more the egg from the incubating medium into a plastic shoebox full of damp sphagnum moss - the turtle can exit the egg and bury up in the damp moss for a few days till the yolk is all gone.

Just make sure everything stays moist...