She had plenty of character
No she didn't.
She was a soldier but that didn't really define her alone.
Lots of characters are soldiers who aren't defined by being soldiers. This isn't interesting.
She wanted to protect people
Lots of characters want to protect people. Still not interesting.
and went against her dad's wishes to do so.
She didn't do it on screen. And she never dealt with any fallout or consequences of making this decision on screen. For all intents and purposes it basically didn't happen.
Both times it comes up in conversation, incredibly briefly, the conversation turns to exploring the rivalry between
Johnny and Jax. That's right, what should have been a pivotal moment in Jacqui's life is actually used to develop two other characters instead.
She found a way to emulate her father by using external cyber enhancements with guns attached to them.
...this is not a character trait. This does not make Jacqui a well rounded character.
Everything Jacqui is in MKX, another character does in a more interesting way.
Cassie is a soldier who spends all game trying to get her team to work together, prove herself and basically earn a promotion. Sonya is a soldier who spends all game trying to juggle her personal life with her career. Jax is a soldier who doesn't want to be a soldier because he has PTSD.
Jacqui is.......... a soldier. The end.
Jacqui has a complicated personal life? Great, let's see it on screen. Where is it? We see Cassie's complicated personal life all game long, so we understand her struggles. We see Takeda and Kung Jin's flashbacks, so we understand something about their struggles.
Jacqui........... says "Jax was just a bit over-protective." The end. It isn't even played for drama, the next sentence out of her mouth is about how he beat the shit out of Johnny hahaha it was so funny.
That's her character in MKX in a nutshell. Cassie gets the entire game to explore her conflicts, Takeda and Kung Jin get a flashback to explore theirs, and Jacqui gets a sentence that turns into a Johnny vs Jax anecdote.