Possible Over watering?

So Coco coir needs to be properly pH'd first and pre loaded with nutrients before you plant in it, unless you bought a product that already is. That is most likely your issue.

Looks like a little over watering going on. Get that soil dried out as fast as you can. Then just sprinkle a light amount of water when the cup feels light to pick up. Then you give it a little splash, not a big drink. It only has the infrastructure to take up a little water, but a huge dump of it.... The result of a huge dump is water logged soil that won't allow for oxygen to get into the space because it's filled with water. They won't breath, they'll get droopy and start yellowing and just look sad. If your really unlucky root rot will set in. You'll know if thats happened by the sad state of which your plant looks, and when you go to move out of your solo cup into your next pot, you'll see sort of amber or, i dunno how to describe the colour, but if they aren't nice and while, but kind of a light caramel colour goin on, thats root rot. That shit will spread and kill your plant. You'll need a cellulase enzyme that eats cellulose aka dead and rotting organic material. I use Hygrozyme personally, but there are other companies that make their own, like sensizyme by advanced nutrients, among others.

Drainage holes, watering daily with right ph and feed 4x if you can, collect all run off, use grafity and trolley, for it never stand in it. Even unbuffed coco will even out. Girl should be fine. Worst case you learned and will lose 2 weeks if second attempt ...

Looks like the 🥥 has not been washed out and buffed properly coursing lock out.id buff with cal mag and fresh ppm to 300 plus one m of hidrogenproxid

1st things 1st. You can't overwater in coco. Unless you didn't punch any holes in the end of that dixy cup. They're really not great to grow in. If you've to uppot within the 1st 3 weeks of growth. You really should have a bigger pot. And not touch a root zone for at least a few weeks. You want to be a simple transformation.. With these cups there's 1 +. You just need to grab a Stanley or knife and cut the cup away. Try not to disturb the roots. If they're bound together. Which if you leave it n that cup for 2-3 weeks. It will be. So you'll lightly have to pull a few roots so it faces down. 90% it the time, they'll just reroot into the new pot. As that is in a small cup. That is a fem seed right? If anything. Id say your roots are finding it hard to breath with a mix of too much light. Your lux should be in the range of 10-15000k. 300-350ppfd for 16-17hrs. If you haven't punch some holes or uppot that into something that the roots have room to grow through therefore taking up air (02/co2)by moving thru your larger pot

I've heard it said you can't overwater in coco, but that's exactly what you're doing. Are you supplying plenty of drainage in your cup? Until rootzones are established I tend to not oversaturate the medium, though I know many argue to soak a pot from the get go. I only water the perimeter until the plants show some real growth, encourage the roots to seek out the moisture that wicks in closer.

Drooping leaves is a sign of overwatering you are right buddy and she is a small plant at the moment so yeah I would let her dry out and then keep eye on here looking healthy though keep up the great work and if you need anymore help my dms are always open to chat about growing. Best of luck buddy :)