I have suggested Glycine clandestine on the basis that all three leaflets seem to arise from the one point and the vein reticulation is not obvious. The shape and the size of the upper and lower leaves are also consistent
When I blew photo 2 up, the leaf reticulation could be seen. So I would go for Glycine sp. I prefer to use whether the plant is stoloniferous (has above ground runners) (microphylla) or not (clandestina) to decide which species. In a small plant like this, I would imagine it is too young to have runners anyway.