Symbolism, Imagery, Allegory
If the knight is a symbol of men's sovereignty, then you can probably guess what the queen and loathly lady symbolize – that's right, women's sovereignty. It's interesting, though, that we have them sharing this role. In the beginning of the tale, the queen takes over the role of judge, so she might represent justice, as well. The loathly lady takes over this role once the knight's 'hearing' has concluded, but she seems to play the role of educator more than justice. However, both women make it very clear that they wield sovereignty over the knight's body. The justice-and-education combination may be in effect in order to give us two of the faces women might wear when they exercise their sovereignty.