She also betrayed the team when they arrested the Avengers. IIRC she was an old friend of Valerie Cooper's and that is part of how she ended up on the team. There is an Avengers West Coast storyline that explains some more of the backstory.
Furthermore, an issue of Iron Man (#207?) that is Julia's first post-Secret War appearance shows why she joined Freedom Force... she was explicitly forced to by Val Cooper and the government.
I'll also note that Jessica Drew only lost her bioelectric powers to Morgan Le Faye... she was still superhumanly strong and could stick to walls after this, as her Wolverine guest apperances show.