all depends on the size of the quick.
my girlfriend is a dog groomer @ petsmart, so we always do all of our animals ourselves.
the nails are similar to a dogs, if you can see through the nail, and see the quick quick just a little bit away from it, dont wanna bleed them.
but if you cant see the quick and with it being so young you may just want to get a nail grinder and grind them. not the cheapest but it works, and neither of our buns even mind it.
after theyre older if u still cant see the quick, just cut off (almost shaving off) a little bit at a time untill u see a little black dot in the middle of their nail(thats when you stop.. lol)
but yeah id just be careful but we cut our thriantas nails @ 9-10 weeks
good luck