Stems?

I agree with the light answers, also what type of soil is that? I don't see any perlite in there. Your poor baby might be in some type of compacted soil and your roots will have a hard time growing . All u will get is a stunted plant.

That's normal at this stage. But maybe also a lack of lights. Provide minimum/moderate water at this stage, the baby does not drink so much. Take advantage to provide more substrate to your pot, you still have some space and is easier to the plant make roots. Good grow!

It is like the other growers sid so... the plant is looking for the light so it stretches. To fatten up stems you can do a god number of things. ( to get a stable stem). Give the stem airlow with a fan....the stem moves alittle little cracks appear in the stem and it fattens up. b) lower the light, so the plant dont have to search the light. Watch out not to burn them. c)dig the stem deeperin next translant or dig some soil around the stem d) go horzontal above the plant with you hand and open the hand , taing the little stem between your finders ( like acigarette) shake the stem softly, repeat it every day. Its like the fan do it.... by moving the stem, little cracks appear and the stem fattens up. I do it on all my plants every day... shake baby shake....

Lower the light a little, its stretching.

Your light is too far away. She's stretching up to find it. Mark the spot for next grow as will want it around there after see your 3rd set . As of now just drop your light a few inches will see her thicken up after couple days

Its normal bro it’s still young, try to put some more ventilation when a bit bigger it will make the stem thicker

Normal, a little stretching but is normal. Wont get thick until later, maybe week 3 or 4