User blog comment:B214/Volume 22 spoilers/@comment-25262334-20160720010158/@comment-1359322-20160720015037

Sona is a good rated King even more than Rias and Sairaorg, that doesn't mean she's more powerful than those two. Same situation here, a good rated Queen doesn't mean a powerful Queen, it just means she's a capable one, like maybe the Queen can make a better judgment than Ise.

Either way, who is the Queen remains to be seen. It could be Grayfia, it could be Venelana, or it could be one of Rias' family maid.