slow grow?

Your ph is likely not ideal. Heavy irrigation is required and very light nutrition to start. My first feed is about day 7 since sprout. It is only a few drop of my 3 part nutrition with calmag. The roots are just getting established, and acclimated as well. She should start growing faster. Can also depend on your light strength. Like intensity in vegging is less. As plant goes through stages intensity increases. Lower light in vegging stimulates more leaves to try to catch as much as it can. If you get too far they will stretch too much. Plant leaves will be perky when they grow if your in the sweet spot.