Lena was captured and placed inside a room on the ship. She was allowed to send a message to her crew which was worrying about her.
Lena informed Bella that if she didn't respond to their calls, there was a beacon inside her body that would send them the signal, and it wasn't needed to tell what would have happened then.
A huge force attacking the cruise ship would surely attract the attention of the Crimson Claw. As such, Bella allowed her to send the text.
Why was Lena being so obedient and not trying to escape even though she easily could? Well, because she doesn't want to go anywhere when her Queen is here.
The feelings Lena carried for her Queen eclipsed admiration and was something like devotion. Lena was devoted to serving her Queen.
She was saved by that woman and was given a direction in her life. Lena has seen Bella's strength and her determination to achieve her goal.
