I would like to send my condolences to this family because it is a terrible and tragic loss. Your post assumes that a license prevents a problem but this institution could have met all licencing requirements (I don't know if it did or didn't) but that really isn't the point.People, these are your children, take nothing for granted. If you are going to place your child somewhere, it is up to you to do your due diligence and don't just ask about credentials. Make sure you see them and research them. Also,
if you are going to work in an environment where you are responsible for the well being of others, you would think you would also make sure you are protected so if something happens, the establishment is able to uphold their responsibility. So on two fronts, it appears there was no real inquiry into the school.
This family is paying a terrible price for because they either took someone's word for the proper credentials, or they just assumed and never asked. It's a shame.
Someone made a very stupid mistake but leaving their carrots out where a child could reach them and choke. The staffing could have been totally adequate (or not) and you can turn your back on a child for a second and in that second a child dies.
A license on the wall would not have prevented this horrible accident. I feel sorry for the teacher as well, who must now be devastated from the outcome of her lapse of good judgement. Most teachers truely care about their students and I am sure this person is a mess right now, not that this excuses the mistake.
The take home message should be that everyone should be more careful about their day care center. Check out what the teacher to student ratio is (the license process does define what this must be based on age). See if you can stop in without notice and check on how things are being run, how do they handle infectious cleaning such as by the diaper area? These are the questions that should be asked. Do they screen workers with fingerprint checks to see if there are child molesters among the staff?
I wish you sister and her family peace as they try to put the pieces of their life back together. I hope that they can find confort in the fact that their daughters death has forced many other parents to re-assess where their children are being watched. It will not bring back their beautiful baby, but perhaps it will prevent another death.