Bloom Bro's has got it on the head,,chili,yeah its exciting but you dont want to ruin your babies,,
,,from personal exp. of making clones,when I tried to clone off a 3 week old seedling, its very hard to get a good clone offa a really small plant,not impossible, but it dose make it alot harder.
Id recommend a 1 and a half - 2 month old mother to take clones from, its easier to use the older branchs for a clone,as they have a higher carb-o-hydrate level and less N present. Having an older branch also means you can get a node under the soil and two nodes above ground,and with that node under ground its easier/quicker at rooting,,
maybe read the cloning threads on here and you will see the age/size of plants most people would use for clones,,but technically a plant can be cloned at any age,,but its not recommended...I wouldnt use that wee seedling for a clone yet,,its well to short...
Also as a part of a plant growing the plant has to be mature enough to bud before it will bud,,so that wee seedling is to small to produce any flowers yet,so the clone wouldnt show sex either(if you see what I mean,,
cloning for sex is the most accuarte way to determine sex, but there are other ways to tell sex...symetrical,two 'pistles' on banch nodes/ main stem,,etc...
hope that helps,take it easy..