A non profit vintage baseball team. She tagged the team in a photo threatening to escalate the drama on her facebook page and county facebook page
Okay, so there is drama on the baseball team, just as there is probably drama between some of the members on the team and as there is probably drama between the different teams. That is not all that unusual.
However, if this former member of your organization is telling tales about the team, similar perhaps to a Patriots' deflate-gate story but with baseballs, and unlike the Patriots the tales are false instead of true, and these tales have caused injury to the reputation of the team or to individual members of the team, to the point where the team loses a sponsor or the team is kept from competition, a legal action against the tale-teller is something the organization can consider.
Threatening to "escalate the drama" without actually escalating the drama, on the other hand, would not be enough to support a suit. Expressing negative opinions about the team (e.g., "The team sucks") would not be enough to support a suit. Telling true but negative stories about the team would not be enough to support a suit (under most circumstances).
Whether there is any legal action depends on
exactly what has been said, how it has been said (e.g., with humor?) and to what extent any falsehoods told are believed by others to be true. If believed true, it then depends on how the community has reacted to what has been said.
A personal review by an attorney in your area appears necessary and is recommended.