I would say thats an enviro problem as much as anything? Try taking her out of the 'clear' cup as she might be getting algae on her roots the soil looks a bit rough too imo
Seriously though just re-pot her in a small 1 litre mixture of proper seedling mix or even coco, make sure its got good drainage. Get a small fan on her if you don't already, air movement is the cheapest plant tonic you can provide, they love a bit of wind them girls... unless its under the doooovaaayyyy
You will see a proper growth burst, she only looks a week 10 days from sprouting to me? Then you can bin it assuming its a grek...
Is there a bit of residue on the leaves like a pale dust? I can't really tell on my crap screen
Good stuff but don't feed with it!