Watch for the hairs. That is the key.
Spotting male flowers proved more difficult for me, but someone
pointed out that male flowers are often on a small stalk where female
flowers are more sitting right on the stalk.
I found that my mothers had to get pretty bushy before I saw what I needed.
Check my "Crop #3" link below. I posted images of each mother and the
pre-flower that I managed to find.
Good luck,
JD