Since Dragon Age 2 is a series whose story/history is based on player choices, it's important to note them for the sake of not only Isabela's characterization, but for the sake of the sanity of any canonmates I may happen to get. Also note that the choices are just based on my personal preference/my playthrough of the game! Also there are SPOILERS. Obviously.

⚔ HAWKE

➳ Female
➳ Rogue, dual wields
➳ Romanced Anders

⚔ DESTRUCTION OF LOTHERING

➳ Carver is killed
➳ Hawke and Bethany join Athenril the smuggler

⚔ ACT 1

➳ Feynriel is sent to the Dalish clan
➳ Hawke helps Ser Thrask, but refuses to kill him. She does agree to at least convince him that the mages are dead.
➳ Idunna is killed when Hawke breaks her control.
➳ Hawke believes there a chance that Keran might be possessed, but advocates for him to keep his status.
➳ Hawke agrees to help Javaris. However, at the end of Blackpowder Promise, she tells him to just leave.
➳ Hawke agrees to lead Ketojan to freedom. When they encounter the Qunari, she refuses to hand him over.
➳ Bethany does not accompany the party to the Deep Roads. Hawke, Varric, Fenris and Anders go to the Deep Roads. Hawke refuses the hunger demon's offer.
➳ Bethany is captured by the templars to be taken to the Circle.

⚔ ACT 2

➳ Javaris is not killed.
➳ Gascard DuPuis is not killed on his first encounter. After the quest, Fenris helps interrogate him, and Hawke kills him.
➳ The Qunari hostages' bodies are not burned.
➳ Isabela allows herself to be captured to reclaim the artifact.
➳ The party runs into Alistair/the Group of Grey Wardens.
➳ Orsino creates a distraction.
➳ The Arishok respected Hawke.
➳ Hawke refuses to hand Isabela over.

⚔ ACT 3

➳ x