My nephew is teething at 6 wks. Is this normal?

Normal yes..... But might not be teething at all. By 2 mos kids start finding their hand, then their mouth, then their hand in their mouth which does not mean we are teething. Normal development. Usually on average it's 6 mos for teething to begin. I think the earliest i've seen a tooth cut through was 2 1/2-3 mos. Hope that helps.
Yes. Although the average age at which the first primary tooth makes its appearance is about 6 months, there is great variability. Some babies already have teeth at birth ("natal teeth"). Teething at six weeks of age is certainly not an indication that anything is amiss.