That woman's name was Raheal, she was another slave, as could be deduced by the chains on her ankles.
But the reason why she was held in such an isolated place, away from anyone's eyes or reach… was because she was bearing the Lord's child.
Since Marwa was too old to make several trips back and forth from the manor to the cabin and back a day, Zarqa was asked to help look after the pregnant woman. It meant that Raheal would have someone popping up to check on her and help her around every now and then, unlike when Marwa used to come by after dinner was served and everyone went to sleep.
She was overly happy with the new arrangement and quickly warmed up to the new girl. It must have been hard, being locked up on your own there for so long. Zarqa had concluded.