I call them Tiny Tia and Little Lulu.
This is just a concept sketch for ANOTHER story idea that hit my head. What all is going on here? Why are the sisters young and in armor? Is this a story based in the past? All these questions except for the last are answered with 'No'.
Time will tell what becomes of this. For now it's yet another concept sketch of a myriad of ideas that come without warning or hesitation.