Her true identity was Jennifer Burke, daughter of the original Miss Victory, who in the 1940s developed the "V-formula" to increase the strength/stamina of allied troops.

The initial formula, V-45, turned Dan Barton, crack covert agent and boyfriend of Laura Wright, into the supervillain Black Commando.

Joan Wayne was able to alter the formula, creating V-47, which only worked on herself and only for a short period of time, and she became the superheroine "Miss Victory".

In addition to permanent super strength and youth, she developed the same paranoia and narcissism that the Black Commando had.

[2] In the meantime, Joan Wayne was replaced by her grown-up daughter Jennifer Burke (the only other person on whom the V-47 would work) becoming the second Miss Victory.