Kind of a dead thread but here's my .02.... I'd go with the bow. Once it's learned it would probably less labor intensive as far as upkeep and replacement. How easy will it be to replace/forge internals for a musket when SHTF. Not to mention the worst case scenario deferences if they were to fail. Deep cuts to worry about infection, or a small explosion in your face. Maybe the family would be better off shooting a bows as well. That might help get more food on the table. I really couldn't see my wife or daughter shooting a muzzle loader. That's just me though..
Either way, try both pre SHTF so you'll be ready should you need to switch or barter! I personally am going to use my *silent* bow/trapping for hunting first to save on ammo anyway. When it gets bad, I don't want anyone to know where I am or what I have.....