No she didn't. She shot down everyone who was standing. Watch it again. Only a few people were left uninjured. Like you said, she shot down the first and second lines, but there were only 2 lines! She even reloaded in between lines...
Calling for surrender after massacring the first line wouldn't suddenly kill her. She wasn't fighting alone for crying out loud. If any of the soldiers decided to throw anything, her 2 other companions would've easily covered for her. And if you pay more attention, she was shooting soldiers who were sitting like ducks.
Face it. She killed everyone not out of necessity, but as Ryll and Kraco mentioned, a demonstration to show their power and brutality when offended.
Everything else, the bayonet fight, the fist combat, the torture, all of it points towards that conclusion. Insisting that she shot with restraint actually goes against everything else in that scene.
To summarize my opinion:
Would the enemies have surrendered if she asked them to after making an example out of the first few by shooting them down? Maybe they would have. Maybe they wouldn't have. We'll never find out now because she never tried. And trying was well within her abilities. She obviously had enough leeway to call for surrender in that scene and to react if the enemies do not accept.