Don't be the one who initiates the page if you don't have the time to act as the "site admin".
Or, whilst you might have the motivation and inspiration to set the thing up, if it later becomes a drag, you are able to grant admin right to another family Facebooker and relinquish your own admin rights.
It helps if you have more than one set up as admin, from the outset, in case of disasters.
The great thing about family pages is that it stops shared photos leaking out to friends and friends of friends. There's always one with share settings set inappropriately, ruining all your efforts to limit circulation of something.