The court used a definition of citizenship in her favor that would have made her eligible to run for president. Had this been Obama, they couldn't have done that because he was born in a class that had doubts and did not meet the characterization of natural-born citizen. Think for a moment. Had Virginia Minor sought the right to run for president instead of a right to vote, how would the decision be any different??
The holding of Minor was that the 14th Amendment did not give women the right to vote. Therefore, the discussion of citizenship was not essential to the result-- Ms. Minor was found to be a natural born citizen, but not entitled to vote because of her gender. Had she been found to be a citizen but not a natural born citizen, she would have likewise not been eligible to vote; had she not been a cittizen at all, she would have not been eligible to vote. The discussion of her citizenship was not essential to the holding, and is therefore dictum.
That's not just me saying that; the court in Wong Kim Ark said the same thing; the court in Ankeny said it; Judge Malihi said it; the case in Virginia last month said it. No case after Minor has ever said that the discussion of citizenship in Minor is a holding or is binding precedent.
As I said above, "the law" is not what people on an internet forum say it is; the law is-- by definition-- what the courts say it is. No court will ever hold that someone born in the United States to parents lawfully here (whether as citizens or legal aliens) is not a natural born citizen unless their parents were foreign diplomats. You can take that to the bank.