How does poet describes Amanda?

The poet is describing Amanda, a little girl who is always pointed out by her mother for her mistakes and how she imagines her life to be. The poet says that the mother is pointing out Amanda for biting nails which is a bad habit. Next she asks her to sit straight without bending her shoulders. Amanda who has habit of bending her shoulders and sitting lazily is being pointed out because her mother wants her to sit in the right posture. At this point of time, when she is being scolded by her mother, she imagines herself to be in a deep green sea. She says that she wants to be the only resident of this beautiful green sea. She imagines herself like a mermaid who is alone there and leads her life in a very relaxing way. She says that she wants to be carried away by the current of water and feel the relaxing environment there.