A good analogy might be that of a captain of a ship or aircraft. On long tours of duty, they go off the bridge/flight deck for a rest and the first officer takes the watch. If something serious occurs, they can expect a call. Similarly, if the new CEO is at home with the family and something serious occurs, I am sure she can expect a phone call.
She's not arguing for that she wants to be home picking the kids up from school 80% of the time.
It would be the equivalent of a Pilot wanting to only work earlies so he could pick the kids up 4/5 days a week.
Now if Jetstar bring in a awesome bidding/rostering system that enables this and Jetstar are willing to cop the cost and inefficiency, then good on her, she is doing something for her employees.
The problem for her is that the family friendly rationale cost money and is inefficient, if they are willing to wear the cost good on them, I for one don't think they will.