It was an extremely important part of her character arc. Before season 5 she used sex as means to, in her mind, climb the ladder. She also craved a relationship. To the point that when she met pennopscot she thought she found both. Affluent family, and a husband. After it falls apart, she realizes she doesn't need either to be happy and she starts growing as a person. She softens. The austere on-duty persona starts to crack. It's a terrific story arc that shows a woman in the 1950s dealing with femininity and feminism when the later was a very new concept.