Floral, I didn't even know there was more than one Aphanes species in the US. The following Weakley snip suggests that A. arvensis has larger leaves. The BONAP distribution maps suggest that the Georgia plants would be A. australis.

Shotweed, Cardamine hirsuta, aka hairy bittercress (or a vey closely related species). A cool season annual that can be easily pulled in moist soils. Any broadleaved lawn weed herbicide will work but try to pull them or kill them before they flower and set seed (which yours have already done) as it has a large seed bank and as the common name implies propels ripe seeds over a large distance.

What are you considering "the weed" in the picture. Is it the broadleaf plant or the yellow tipped grassy plant? The yellow tipped grass looks like the seed head on buffalo grass to me. If you are watering daily, stop that. Watering too frequently will turn a lawn yellow. Here's a picture from morpheuspa of his Kentucky bluegrass lawn versus the other KBG lawns in his neighborhood. He watered his once a week while the others watered every day. If you are currently watering every day, you'll have to wean it off of frequent watering to get up to deep and infrequent watering. I'll give you the deets on that if you want or you could look for 'deep and infrequent' in this forum.