From my basic understanding, as it may still be early in the season, and as the sunlight is less intense, they may be "reaching". It's pretty normal if you ask me. Most of their energy has been spend on
root development, and now it sounds like they are just starting to photosynthesize. Couple inches from the base of the plant to the first nodes are typical in seedlings, depending of variety, from my
experience. I honestly wouldn't worry about it much, once they put on their 3-4th leaf sets you can give them some food, unless it's already in the soil. For my window sill herbs, I like to turn the pots 1/4 of the way aorund a 360 degree axis every couple of days for good light distribution. A little
compost topdressing usually straightens things out for me, as well. Hope this helps.