Women's Wrestlers With The Most World Titles (Across All Major Promotions)
10. Irma Gonzalez (7)
5 Mexican National Women's Championships
2 UWA World Women's Championships
Irma Gonzalez is the Rikidozan of Mexican women's wrestling.
She was among the very first wave of women to step between the ropes in Mexico in the early 1950s. Trained, among others, by lucha libre royalty Gory Guerrero and Jack O'Brien, she was the second ever woman to win the Mexican National Women's Championship in 1955 (the first women's world title in the history of Lucha Libre) which was then sanctioned by the EMLL (predecessor of CMLL).
Note that this is where the limitations of a list like this should be acknowledged: Wikipedia or CageMatch only teach us so much, and the history of that title is unrecorded for various periods of time, especially in its early days. In those days, titles were not spung around as frequently as today, but for all we know, Irma might've won a couple more National straps.
Same goes for the UWA Women's World title. Wikipedia claims there has been no recorded defenses since 2003, but in her recent retirement post, Miss Janeth claimed she retired as the owner of the title, vacating it after going undefeated for 23 years. That would seem to indicate it was still active and competed for.