She did win a "Nobel" prize for her work, but I wouldn't say that she "refuted" the Tragedy of the Commons. It seems more like she found that it is possible to avoid the tragedy with the right systems in place. From the article:

Ostrom’s answer was Governing the Commons, a landmark 1990 book that set forth some of the basic “design principles” of effective, durable commons.

The article goes on to say:

has been how communities of resource users develop social norms—and sometimes formal legal rules—that enable them to use finite resources sustainably over the long term

The key point there is that the "Tragedy" is the default, and you can only overcome it with societal norms and/or legal rules. Unfortunately, that means that a commons will often be over-exploited, which is a tragedy.

The prime example of that is the atmosphere and atmospheric CO2. There is no legal framework over the atmosphere's commons because there's no world government that can bind everyone. And, the commons is the ultimate prisoner's dilemma situation. If everyone cooperates everyone wins, but if anyone defects, the earliest to defect win the most.

Ostrom found that commons must have clearly defined boundaries so that commoners can know who has authorized rights to use a resource.

So, the atmosphere is once again a terrible "commons" to govern. It doesn't have clearly defined boundaries of any kind.

Commoners must be able to create or influence the rules that govern a commons, Ostrom noted. “If external governmental officials presume that only they have the authority to set the rules,” she discovered, “then it will be very difficult for local appropriators to sustain a rule-governed CPR over the long run.”

More tragedy for the atmosphere. The only possible way to regulate that is a government that covers 8 billion people, because it's a commons used by 8 billion people. But, that means that external governments have to set the rules, which she found was a way that regulating commons failed, leading to tragedy.

The guy who came up with the term "The Tragedy of the Commons" seems like a pretty awful guy, and he used it to justify some pretty awful things. But, he was specifically talking about these hard-to-manage commons affecting the entire world, leading to overpopulation and a resource crunch. While Ostrom's work is encouraging in that small-scale commons can often be managed, and in some cases have been managed successfully for hundreds of years, it seems like it's still true that an unmanaged commons will be ruthlessly exploited, and that's how we're in a world where the sea level is about to rise and drown most of Florida.