He he I thought you actually are working WITH a child!
That would be illegal child labour! Ok, definitely very very difficult if both of you fly, even if its with the same airline. Do the carriers you intend working for offer daycare, as some do?
If youre considering a 'live in au pair', I hope for your sake your boyfriend/husband is a CAPTAIN-on any other flying salary that would be DARN unaffordable! Good luck!