>>122158827easy
sasha is ID as she is very impulsive driven and has little care about anyone else
Marcy is the superego as she litteraly symbolises the mind and is provides guidance with her knowledge
so anne can only be the ego, especially from a series perspective as she is the main character and we experience most of the action from her point of view also, naratively, she is very much influenced a lot by both marcy and sasha where sasha was the more dominant partner in that relationship, comparable to a child that is egoistic and first has to learn the meaning of values.
As she uncouples her self from sasha and she comes closer to marcy, not only she engages into a healthier relationship, she also matures mentaly akin to a child growing up and taking responsebility and thus can also achive a better relationship with her ID aka sasha thus finaly mature into a healthy adult that can form a symbiosis with her strive for inner fullfilment and with the needs of her environment and the society as a whole
aka marcanne is canon lol 
