Complex sentence: The editions were actually made by Bowdler's sister, Harriet, but they were published under Thomas Bowdler's name, probably because a woman could not then publicly admit that she understood Shakespeare's racy passages.
Split into simpler sentences: The editions were actually edited by Bowdler's sister, Harriet, rather than by Thomas. However, they were published under Thomas Bowdler's name, because a woman could not publicly admit that she understood Shakespeare's racy passages.