The best replacement for supergirl is wonder woman.

The best alternatives to supergirl are rated as following:
★★★★★  wonder woman
★★★★  batgirl
★★★  powergirl
★★★  mary marvel
★★  galatea
★★  she hulk
★  superboy
★  power girl
★  supergirl
★  nuclear man
★  superwoman
  catwoman
  kryptonite
  ms marvel
  she-ra
  starfire
  lex luthor

Your alternative for supergirl is not listed? Suggest!
Speaking about supergirl, one probably shouldn't forget about superman.

Other search terms related to supergirl and their ratings are:
★★★★★ superman
★ batgirl
You have in mind a companion for supergirl and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of supergirl in all years. Click on graph for more.
supergirl
wonder woman
batgirl