The "old ladies" notion probably comes from the fact that there many more widows than widowers. Old widowed women use church largely as a social outlet.
Some of these stereotypes are from tracts that I have received from people. One tract showed a younger man in church who was daydreaming about a baseball game that was coming up. The tracts never show women as thinking about matters outside of religion while at church.
At one of my Methodists services years ago, a minister from China visited. He said that Chinese youth viewed church as "for old ladies" even in their culture and the people at church laughed.
Even to this day, the word "church" uttered evokes images of pews filled with old women in dresses and veils or scarves over their heads. The "church" is considered a female entity as is regarded as a "mother" of sorts.