Question about Terminator season finale.

I haven't seen this brought up yet.. There is still one point that
confuses me.  The hispanic girl (who I do not know if she has a name
or not) shows up at the Connor's door and drives them to the location
where the killers were.  (I'm assuming they killer her boyfriend,
brother, something like that)  But when everyone gets out of the car,
Cameron says to her, "Do I need to kill you now?"  The girl doesn't
respond.  Then Cameron hands her the gun.  Why?  Why would Cameron
feel the need to kill the girl to begin with, and why hand her a gun
after asking such a thing?