Kathy Kane is the Silver Age Batwoman, a love interest of Batman, and a completely different character from the 52 Batwoman Kate Kane. After Kate Kane's introduction, Kathy Kane was known as Kathy Webb-Kane and after Flashpoint, Katrina Netz.
This is going off the debut of comic book characters. In the cases of characters who were introduced in other media originally and added to the comics canon later along (ex: Harley Quinn) it'll go by actual debut year.
