If his goal was to take over Mandalore anyway, then I sincerely doubt Satine would have escaped unscathed, regardless of her affiliation with you.

[As he's proven time and time again, Maul reveled in his ruthlessness, celebrating every evil victory and every vicious notch he carved into his belt. Satine's death and the impact it had on Obi-Wan was just a bonus.]

Her death is not on your hands, but on his.