There are no current plans to cross over The Flash and Supergirl, according to Greg Berlanti, who runs both shows.
Over the holiday weekend, rumors hit that Supergirl would visit Central City and meet with the cast of The Flash. Early reports indicated that it would be a condition of Supergirl's full-season pickup, in order to goose ratings for both shows during May sweeps.
Today, though, Supergirl got an additional order of seven episodes and, following a screening of The Flash/Arrow: Heroes United, this week's two-night crossover event on The CW, Berlanti denied the reports.
"Only because we just received the pickup," Berlanti told reporters when asked whether preliminary discussions for such a crossover had happened. "But not at this point."
Supergirl airs tonight, bringing in Red Tornado, while The Flash and Arrow's crossover episodes will air tomorrow and Wednesday. All three series air at 8 p.m. ET/PT. CBS carries Supergirl and The CW has The Flash and Arrow.