MissJeanLouise started life as Jean-Louis Dehaine (deux-N) - Lou to family- in the Alsace-Lorraine territory of France. As a child and adolescent, Lou never seemed to fit in, and never seemed to be bothered by it, relishing in singularity.
When the time came to choose a life path, Lou went to the only place he could think of that would accept his singularity without judgment, and may even embrace it a bit: the French Foreign Legion.
Lou was well-liked and respected in the FFL, rising quickly through the ranks to Colonel in only 10 short years (unheard of! which is why they changed the requirement to 14 years in after his tenure).
After conquering the realms of men is such a short period of time, Lou (always deeply curious) decided to transition to Jean-Louise, convinced that his feminine character being suppressed is what created the distance in him with other people.
With the limitless support from her comrades in the FFL, Jean-Louise blossomed wonderfully, if a little aimlessly and happened upon a singular phenomenon in one Misha Collins while freeing cross-species animals from testing facilities with unendurable living conditions, who roundly appreciated her singularity and created an advisory position for her in his life in general. Who doesn't need an advisor??
MissJeanLouise's history with singularity as well as her history of leading men, she has proven to be the caring guiding hand with patience (to a point) Misha needs to accomplish his goals of spreading silliness and kindness through the world.
Now MissJeanLouise is in her element, conquering the world of myshas and Mishas.