Posted on a FB page I look at...it's not familiar to me. Says it spreads like wildfire, sun or shade. Easy to pull. Small white flowers.
I am not at all convinced the leaves go with the flowers. The second picture, as far as I can tell from the blurry photo, shows Shepherd's Purse, Capsella bursa-pastoris, or a similar Brassicaceae which I am not familar with. The leaves are something different. Possibly something in the Polygonaceae???? Do you know the size of the leaves?