From The TimeSplitters Wiki

Corporal Hart
Unlocked by	TS2: Default TS3: Future Perfect on Normal
Species	Human
Size	Normal
Accuracy	10/10
Agility	6/10
Stamina	6/10
Fire Proof	10/10
Shock Proof	10/10
Default AI	5 stars
Native TimeZone	2401
First Appearance	TS2 Story Mode
Relations	None
Games	TS2 & TSFP

Corporal Hart is Sergeant Cortez's 'sidekick' in TimeSplitters 2, until she is killed by a Reaper Splitter. She speaks with a strong Brooklyn accent and has various robotic body parts.

TS1 Gesture	N/A	TSFP Gesture	Points at screen and says "Locked, cocked and ready to roll!"
TS2 Gallery	Not just an excellent soldier, Corporal Hart is also an expert with all kinds of mechanical and computer technology. She has found her servo-enhanced Tritium Exo-Arm to be a very useful aid in battle situations.	TSFP Gallery	Cortez's old sidekick. Who knows, if she hadn't caught one in the kisser back in TimeSplitters2 she might still be around, Oh, I see, you've completed the story game so the TimeSplitters never existed and she didn't die. Well, how come there's a selectable TimeSplitter character then?

Her Return

Whilst Cortez jumped throught the Time Portal, Hart stayed at the controls, alot like Anya did only without communication. Hart is killed by a lightning bolt shot from a Reaper Splitter near the end of TimeSplitters 2, however she reappears in TimeSplitters: Future Perfect. However, since Cortez defeated the TimeSplitters and destroyed the Time Crystals, causing everything they had done not to happen because, which caused the Timesplitters not exist, and therefore Hart was not killed and thus reappears in TSFP.