Yellow green leaves

You need to link your question to a diary! This will give us much more information you might not think is important... But just on what you've said and what the pics show, it looks to me like she's getting a little hungry. I'd start some nutes at 1/4 strength. Always make sure you have some runoff (about 20%) or you'll get a build-up of salts and nutrients which will lead to more problems. Good luck!

With my seedlings I only water every 48 hours , let the medium dry out so those roots go looking for food and create a big base to build on , additionally I use a heat mat under the seedlings to draw the roots down in off cycle and to create humidity, I also feed nutes right from the start of week two , starting at 20% then building up to 100% by week 4 or 5 . I think maybe your roots need a little air in the form of a dry out , make sure the medium is airy and water can get out , then bust those nutes in , Mumma needs to eat .