Monica Geller

Monica is Ross's sister and went to the same high school (Lincoln High School) as Rachel. She used to be fat until she overheard Chandler telling Ross in 1986 that he didn't want to be left alone with Ross's fat sister. She then lost about 10 stone in one year to get back at him. She is obsessive about cleanliness and following the rules, and nothing she does can please her mother. She's very sporty, plays tennis and has tried to get Chandler fit in the past, to no avail.