Margaret was born in an army hospital, and because of her family, was destined to join the army. When she was young her parents moved quite a lot and this had such an impact on her she had trouble even when she'd grown up. She gave up making friends at new schools because she couldn't stand the hurt anymore at having to say goodbye all the time.

When she grew older she was stationed in Tokyo before going to the 4077th where she became head nurse [in charge of the nursing staff]. Here she met Frank Burns, and his own love of feeling patriotic and following rules attracted her and the two began a long affair.

One time when Margaret was in Tokyo on R&R, Lt. Col. Donald Penobscott proposed to her [her beauty and all that] and Margaret accepted him, as the thought of marriage and settling down was what she wanted out of life, instead of meeting a married man behind tents secretly [maybe also because Penobscott was a 'trophy' husband]. When Margaret came back to the 4077th and told Frank about her engagement, he went crazy and was sent home, where, much to the annoyance of Hawkeye and BJ, his army-madness earned him a promotion to Lt. Colonel.

However, with Frank gone, and her fiancé stationed in Tokyo, Margaret seemed to have no real friends in the camp as her relationship with Frank had led her to become as strict and interfering as he was. She had difficulties fitting in, having never learnt [after her youth] how to become close to people. Only married a short while, and not having really benefitted from Donald, who constantly cheated on her, Margaret divorced him and remained a single woman the rest of the show. It was then and only then that she slowly but surely began to change. She always stayed 'an army-brat', but around the people of the 4077th, and away from Frank's influence, she became a much more understanding person. She mingled more easily with Hawkeye and BJ, and became a good friend.