Plants suddenly stopped growing!! help plz

The one plant that is a little bigger is just some bagseed from midgrade bud i got a while back. My first seed i germinated before I got the others, which are a strain called Rocklock (Rockstar x Warlock), which I think is an 80% indica/20% sativa strain. Got them from a friend who had bought the seeds and grown his own and had more from his plants. So not directly from a seed company but from a really good source who knows his stuff. The first plant is about 2-2.5 weeks old and the smaller ones are about 1.5-2 weeks old.
Thanks for the info!
I guess i'll just wait it out and see how they do.

Ok so I really need some help now. I got up today and my first plant, the bigger one, had like completely wilted and died- all of the leaves are shrivelled up and it does not look good... i'll post a pic, its from phone though so not good quality.
I could srlsy use some help on this, the other plants look like they might be starting to go too- any advice would be appreciated.

Also on my younger plants some of the cotyledon are turning yellow and then an orangeish color- do you think I am burning them? Is the temp too high?

anyone? its quiet in here... [bump]

Ouch. Not easy to tell ...soil looks dry, but wilting looks like water droop.

Temps?

What's the temperture in your grow room? I would say its lack of nitrogen in the soil from your discription of the plant but from the picture, plants that small don't need much of anything for nutrients except water and light. So I would make sure the tempertures aren't getting too cold in your room at nights and I would definetly try to give it more light.