This question specifically deals with the Catholic doctrine of the perpetual virginity of Mary.
Matthew 13:55-56 reads:
Isn’t his mother’s name Mary, and aren’t his brothers James, Joseph, Simon and Judas? Aren’t all his sisters with us? Where then did this man get all these things? (NIV)
I have read that proponents of the doctrine claim that the word translated as "brothers" in Matthew 13:55 does not necessarily imply biological relationship (http://www.catholic.com/blog/matt-fradd/jesus-had-brothers). My question then, is whether the word translated as "sisters" has the same ambiguity?