I've only seen Northern and Guadelupe Fur Seal, and Steller's Sea Lion with good views, and have no personal experience with either species under consideration.
Studying Shirihai and Jarrett, it seems that South American Fur Seals have nothing like as pointy a face as the ones I'm more familiar with, and I think that must make it harder to separate the females from Southern Sea Lions. The photos here don't show the flipper structure too well, which would give another pointer.
Nonetheless I'd agree with John that the dark animal in the Pic 2 shows a male, and that this doesn't look like a Sealion. However, the animal in Pic 1 has a fairly blunt muzzle as well as tiny ears, and strikes me as a credible candidate for Southern Sea Lion, and the same features then make me wonder whether the female in Pic 2 might not also belong to the same species.
(Googling for images seems remarkably useless, showing obvious images of the other species...)