Ridley Scott did it first. For that matter, Carpenter did it to an extent with Jamie Lee Curtis in HALLOWEEN. And you can point to several other examples in the time period, Carrie Fisher was a feisty princess who would pick up a blaster, Karen Allen got to drink guys under the table and blast away with a machine gun in Raiders. Tyne Daly got to be Dirty Harry's partner in The Enforcer. You had Cleopatra Jones and various leads in samurai ninja, blaxploitation, and spaghetti westerns as well. Heck, Jane Fonda strapped on guns 20 years prior in Cat Ballou.
Now, Cameron may have been the first to do it as the lead character in a big budget, serious Hollywood action movie, albeit following in Ridley Scott's footsteps, and had stuck with it longer, but it's not like Cameron was dozens of years ahead of his time. Or the first to come up with the idea.