Did the Wife have reason to feel jealous of this young girl in the house?

After a long time without seeing her step-niece, she went to spend some time at the house with her step-uncle and his wife, and his wife, who was already quite jealous, became even more intense about this, as she saw how sensual and provocative, always exciting everyone with her smiles and looks and not to mention that she always took a shower with the door open, just to know that she was being watched...