small plants

The substrate doesn't seem to be of very high quality. Which one are you using? They seem slow for 7 days since planting, but some seeds can take up to 10 days to germinate. My advice: don't overwater. Cover them with the top half of a bottle without the cap to maintain a high humidity ratio. Adjust the lamp to a distance that gives you 250 PPFD at zero height from the substrate (I recommend Photone). And be patient in the first weeks. They are slow at the beginning!

i definitely think the substrate could have some more perlite or similar in it. with high water capacity "soil," you want near 50/50. Something like coco only needs 30% because the water retention is 2/3rds of your typical "soil" mixture - all other factors remaining the same. But, i also think you are giving too much light based on seedling in front/right of first pictures. all 3 growth nodes have very little space between them. that means the light was probably too close too early. you may very well give more than that when the plant is mature, but early on you have to watch the distance between growth nodes ("internode" length) and adjust accordingly. if all the leaves look like they are tightly packed, it's too much. too much stretch needs more. Also, some of these look lik ethey just sprouted vs 1 week above ground. are you counting 7 days including the timem it too to sprout? count from the time it started receiving light (sprouted) and it'll be a more consistent timeframe. how much light it receives is the single greatest factor, even if a seedling comes packed with 'some' power its own growth for a short period of time. I doubt those plants with 2 cotyledons and virtually no sign of 2nd set of leaves is 1 week old from sprout, but i've been wrong before, too. it is slow at first. it's an exponential growth rate up to a point later on, but starts slowly.

The ladies should really have grown much further by now. I suspect issues with the substrate (not fluffy, no airflow) and/or the watering (too much water). It's really difficult to assess without more information on that.