A hardworking Monica is introduced in the pilot as one of five close-knit friends who live in New York City, including her older brother Ross (David Schwimmer), neighbors Joey (Matt Leblanc) and Chandler (Matthew Perry), and former roommate Phoebe (Lisa Kudrow).When her privileged, inexperienced childhood best friendRachel (Jennifer Aniston), with whom she had long lost contact, suddenly arrives in her neighborhood unannounced as a runaway bride after abandoning her own wedding, Monica allows her to move in with her while she attempts to reorganize her life, and the two reconnect.
Monica begins dating Dr. Richard Burke (Tom Selleck), an older man who is also one of her father's best friends and 21 years her senior. However, the couple mutually agrees to end their long-running relationship after realizing that Richard does not want children, while Monica aspires to eventually raise a family of her own one day. While in England attending Ross' second wedding, to Emily (Helen Baxendale), Monica sleeps with Chandler. Initially supposed to have been a casual, one-time thing which grew more recurrent, Monica and Chandler eventually develop feelings for each other, but attempt to conceal it from their friends for as long as possible. After finally revealing their relationship to their friends, who are delighted by the news, Monica proposes to Chandler, and they marry.
After several failed attempts to conceive a child of their own, Monica and Chandler discover that they are both infertile, and ultimately settle upon adoption as an alternative, deciding to adopt the yet-to-be-born child of expectant single mother Erica (Anna Faris). The couple is very much surprised when Erica gives birth to twins, and name the boy Jack after Monica's father, and the girl Erica after her birth mother.
