She barged her way into your home without permission despite not knowing you that well and dumped her child on you despite you refusing. Then she bolted knowing that you had refused. And this was for an overnight visit to boot. Not maybe an hour or so, overnight. Because she had failed to make proper arrangements so she could go to work. It's not like this was some emergency.

Saying "she went about it the wrong way" is fairly akin to saying Bush went about it the wrong way. Shouldn't do it at all =/= went about it the wrong way

I'd have called CPS. You do not barge into somebody's home and dump your kid on them against their will - particularly somebody you don't know that well. It's totally irresponsible and actually pretty dangerous. For all she knew you could be abusive.