Gamora, Thanos' (adopted)'daughter, the most dangerous woman in the universe, is taken.
Captain Marvel(Aka Quasar) is the lesbian lover of Moon Dragon, a bald telepath are both key figures previously but not in the current line up.
I'd laugh if she played Groot who is a massive sentient tree.
Mantis, again a plant, but a Hippy plant in danger of smoking herself, monk(nun?) kung fu alien hottie.
IMdb has Yondu listed which is the classic team form the 70s, which opens up Karens possible role completely unless she's just Starlords crying human wife back on earth who needs to be saved...
Neblua? Evil space Tyrant criminal who Thanos the nihilist death worshipper was not happy about hearing that she had been lying for years to any one who would listen that she was his biological daughter. After they beat each other up, the Mad Titan used the Infinity Gauntlet to adjust time so that he had fathered her after all.
NIkki is a joke. The flaming hair is cool?
Starhawk is a possibility? That's a husband and wife genderbending sharing abody and ultimate power.
I wonder if karen is going to use her real accent?