You consider it

Dobra's readiness to sacrifice herself for her daughters is impressive and moved you, even if you can simply refuse her as their lives are already in your hand. That, her gracious and polite nature, along with other things, has created a positive impression of her, regardless of her origins.

"And where will the girls go if we let them free?"

"To wherever fate will take them," Dobra replies.

The answer is something you expect from a barbarian, the survival of the fittest. But, even if her daughters are raised to be competent warriors, and you provide them with food and weapons, you believe that there’s a high chance they won’t survive. Then again, that’s the best option Dobra can hope for, to safeguard their wellbeing, even for a moment.