I have an almost 4 week old Silkie that does the same thing - he/she rushes toward me when I open their side of the coop up to check on them. The other 4 week old silkies run away and the 5 four week old lavender orpingtons try to hide behind the silkies
I touch them all daily like I did with my other clutches. My older chicks (16 weeks and 12 weeks) will let me feed them mealyworms from my hand but I won't let me pick them up - except for my 16 week old rooster - he hardly eats from my hand.
They could just be exploring food options, my lot have always rushed over and pecked my fingers and fingernails when they are feeling brave, they soon stop when they realise its not edible. I tend to hold treats for them now and they back away afraid still of anything new.
But there is something about fingers that just seems irresistable to chicks, I wouldn't worry.
I guess this is what's going on with my 6 weekers, either the 2 are fighting over rooster attention or he is picking on them, I saw a couple feathers lost, at this stage they can't afford to lose any feathers since they're just getting them all . Not very happy bout that.. I guess I'm just going to watch them and maybe separate them if it gets worse?