can my wife's boss really fire her after her bosses child broke something of my wife's and she confronts them

Unless your wife has a contract which states either that she is employed for a guaranteed length of time (i.e. two year employment contract) or that she can only be fired for the reasons, and/or pursuant to the procedures set forth in the contract (i.e. "employee can only be terminated for good cause as defined in this agreement"), your wife can be fired at any time for any reason not prohibited by statute (e.g. race, religion, gender, etc.)  It doesn't have to be fair.