"If you ask my opinion, I would say that woman is a toxic person that should undoubtedly be put in her place by the King. Her decision to come into your room and lock you in was a strange behavior and should be looked into by the one involved."
Bessie had said this because she was worried for Elizabeth and how that bitter woman should continue to coexist together with her in the Palace. What if Agatha succeeded in pushing through her threats or came to hurt her in the long run? Bessie would therefore not have any harm come to Lizzie's health from that woman! Under her watch, such lowly esteemed and bitter tongued Princess had no right to threaten her Elizabeth in the way that Agatha had just done.
Not under her watch was Bessie about to allow that misbehaviour to lay low.