Yes but church activities could be anywhere from 5:30-10PM. So could have been perfectly void of witnesses. And the county fair was going, which is a major annual event. Brooklyn, IA could have been eerily quiet that night.
It isn't just a witness to the moment something happened to Mollie. It may be seeing SO and SO at the store. Or not seeing so and so. Or so and so's truck or car looked different or was parked somewhere or hasn't been seen in a while or ...
And on the positive side - more events mean more traffic and 5:30 is normally when folks are coming home from work or getting ready to prepare dinner. So that too may help investigators know who was where when. Or who was not where someone expected them.
I am also right with OTTO about the hunting or fishing places. The hunters and fishermen may know of a trail or a road or cabin.
This is summertime and folks travel. IF someone knows of anyone's home being vacant they should let police know.
Honestly unless someone swooped into town and quickly determined to make contact with Mollie, chances are, there is a connection where Brooklyn goes - either for Wednesdays or in general- with the person who can help police KNOW what happened to Mollie.
And the good people of Brooklyn outnumber whomever that was in my opinion by at least 1,000!
Folks need to really think back to July 18th and what they saw and heard. And for some, it may be what they saw or heard the next day or during this 12 day period of time. It was supposed to be stormy - maybe seeing someone who looked like a wet rag, even more wet than one would expect.
A young woman's life may depend on folks giving the police a morsel of information. IF enough folks do it, LE can and will build a chain of evidence and use it to find Mollie.