To answer your question, yes, the same ambiguity is attributed to the word translated as "sisters".
There are three ancient views regarding Jesus' "brothers" and "sisters". They are summarized in an appendix to Laurent Cleenewercke's translation of the Eastern Orthodox Patriarchal Text (The Eastern/Greek Orthodox Bible: New Testament, 2011):
The so-called Epiphanian view (named after St. Epiphanius of Salamis
in Cyprus) is the traditional position of Eastern Orthodoxy and the
preferred exegesis of the Greek Fathers. It holds that the brothers
and sisters of the Lord are most probably children of Joseph by a
previous marriage as well as other close relatives such as cousins,
The Helvidian view (named after Helvidius who was Jerome’s opponent in
the controversy) is that of most Evangelicals and Protestants today:
it holds that the “brothers and sisters” mentioned in the New
Testament are children which Joseph had with Mary subsequent to the
birth of Jesus.
Finally, what I shall call the Jeromian [or Hieronymian] view is named after St.
Jerome who did not accept the idea that the “brothers and sisters”
could have been children of Joseph (whose virginity he also sought to
uphold). Instead, he proposed an interpretation of the Scriptural data
which concluded that the “brothers and sisters” were in fact close
cousins. This is the preferred (if not official) position of Roman