The yellowing of the leaves is normal. those 2 leaves are only sprouted from the seed to start photosynthesis and start up the plant, they will wilt and die off as it matures. The plant however, is really small for 3 weeks. I would expect most plants at 3 weeks to have 4 or 5 sets of leaves and be maybe 1 ft tall. Perhaps lighting or container issues?
yes im countig 3 weeks from seed germination took 1week to germinate that plant is unknown but i have now 4 white widows they have 1 day old without counting germination here some pics took them today W.W#1 W.W#2 W.W#3 W.W#4 i hope now they grow good and healthy