I've wondered this before.

She might have known, but was willing to overlook it, being the psychotic lioness she is. If she didn't know though, that would help explain why she is so anti-Simba, having only heard one side of the story.

She might have known that.

she loved scar more and wanted kovu to kill simba and theres nuka who was not chosen

Even if she knew Scar killed Mufasa, then she would say "You kicked Scar!" instead of "You killed Scar!", so no.