We don't really know anything about the other District 12 victor who wasn't Haymitch, except the facts that they existed and that they died prior to the start of the first book.
It's important to be aware that the Hunger Games Wikia is extremely unreliable. Even among Wikia sites, all of which are editable by anyone and many of which are unreliable sources of canon information, the Hunger Games Wikia really stands out as being full of unsourced and/or clearly wrong nonsense. For example, see this page (also this answer), which says (without a source, naturally):
According to the Capitol, Panem has a population of 4,556,778 people. However, adding up the known populations of the Capitol and 12 districts gives it a total of only 1,905,286 people.
So ... not only is the population of Panem known down to the last decimal place (which precise moment does this figure come from, I wonder - between which births and deaths?), but it's also a figure which consists of 4, 5, 6, 7, 8 in the right order? What are we here, statisticians or numerologists? I really can't take this seriously.
In this case, I can see one possible source for the misinformation: the following book quote.
In the history of the Games, there have been seventy-
five victors. Fifty-nine are still alive. I recognize many
of their faces, either from seeing them as tributes or
mentors at previous Games or from our recent
viewing of the victors' tapes. Some are so old or
wasted by illness, drugs, or drink that I can't place
them. As one would expect, the pools of Career
tributes from Districts 1, 2, and 4 are the largest. But
every district has managed to scrape up at least one
female and one male victor.
-- Catching Fire (emphasis mine)
It would be possible to misinterpret this as meaning that the two District 12 victors prior to the Seventy-Fourth Hunger Games must have been one female and one male. However, because this quote is from Catching Fire, in the context of the reaping, it just means that it is possible to get enough tributes for the third Quarter Quell. The "at least one female and one male" victor from District 12, in this context, refers to Katniss and Haymitch+Peeta. So it doesn't tell us that the first District 12 victor was female.