About

Monica Geller

Monica is the younger sister of Ross Geller, and there is a great deal of competition between the two. Ross was often mean to her as a child, although she has since forgiven him. Monica and Ross often fall back into childish "brother/sister" arguments, especially when their parents are around. Monica feels her parents favor Ross - her mother tends to be especially critical of her and has sometimes forgotten that she has two children. Her mother also is always telling her to get married. Monica's father is Jewish and, although she never shows any religious or ethnic identification, she is sometimes identified as Jewish by others in the group (as in Phoebe's holiday song "Happy Hanukkah, Monica" line).

Ross Geller

Ross is the older brother of Monica Geller, and was often favored by their parents (particularly their mother) over her.

When he was born, he was described as a "medical marvel", since his mother was originally believed to be barren (though in one episode, his parents say that they had to get married because Judy had gotten pregnant with Ross). The two siblings are extremely competitive as was demonstrated in 'The One With The Football', where it emerged that every Thanksgiving during their childhood they had taken part in a football match called 'Geller-Bowl' (Chandler insisted that the two 'say that with pride'). This continued until one year Monica broke Ross' nose, and their parents forbade them from ever playing football again. Their father, Jack, threw the trophy, which turns out to be a troll doll nailed to a 2x4, into a lake, from which Monica later retrieved the trophy.

Source: Wikipedia.org