Bea was Queen of Unaroyal during and after the Battle for Gobwin Knob. She committed suicide by walking through a portal to the Magic Kingdom, ending her side and disbanding all her units, which she had sent out of her capital, thus denying them to Gobwin Knob's forces. She also ordered her Chief Warlord, K.C., to destroy her daughter, the Decrypted Princess Cruz, though K.C. and his stack would be decrypted after succeeding.
She may have been Heir to the throne of Unaroyal. With her gone, there was no hope of reviving Unaroyal at a later time.
Real World References
"Queen Bea" is a homonym of "Queen Bee," a reference to the insect with associated cultural connotations.