Isabelle is very much the opposite of Bertha. She's a bit more reserve, lacks confidence in herself, is a Pureblood and tries very hard to be the perfect house wife, mother and socialite. Isabelle was a Slytherin (1961-1968) like her eldest sister Beatrice. She was a Prefect for her 5th and 6th years and then Head Girl in her 7th year. Her best subject was Care of Magical Creatures and did not participate in other activities aside from her Prefect/Head Girl role.
Following Hogwarts, Isabelle moved back home and began to take her role in the Pureblood society. She attended various functions, tea times, charity event planning sessions, etc. with her mother and sisters. It took her about 6 years to finally annoy her father so much that he arranged a marriage for Isabelle. She was married to Gregory Goyle III (INSERT SHAMELESS PLUG HERE -- IF ANYONE IS INTERESTED IN APPLYING FOR HIM, I WOULD LOVE YOU FOREVER!!!!!) in 1976. They tried for a child immediately, though weren't successful until the beginning of 1979.
Now, Isabelle has a three month old
SO! Isabelle (who does not go by a nickname, save for "Izzie" to her sisters and husband) needs friends, enemies, past love interests, former Housemates, A HUSBAND (HINT HINT HINT), etc etc etc. She's a DE sympathizer/supporter as her husband is a DE (outer circle). You can read more about Isabelle here. Yay! (: