If you haven't already, You can ask her yourself how you can make it up to her, and you can explain that your memory got mixed up. As another poster suggested, tell us what you told us here.

But she might just need some time before her anger for what happened dissappears or lessens to the point your relationship can resume back to normal.

I applaud you for reflecting on the event and realizing you were wrong.

Did you have stress building up towards her or something else, before you had the argument?