Seems like you've got all that under control.
My problem is that I'm impatient and even though it might not seem like it, they are growing under ground, and some genetics just take longer than others.
I over watered mine because I couldn't leave them alone, and gave them poor light... I've seen 9 day old plants that are bigger than mine are now at 4 weeks...
I don't think your plant looks unhealthy - at this stage, less is more. I personally would avoid the feed, seedlings usually have enough in them alone for 2 weeks, and if that soil mix is too hot as mentioned above?
I reckon just warm her up and sit tight! She will explode soon
Sent from Space
Ok cool cheers mate,yeh the soil is a seedling mix from Bunnings i normally raise my baby's in the mix with no probs, but due to gnat issues i thought i would try something different. Put some heat on her see how we go.