The photo being shared along with this accusation shows a tricolour flag that some participants were holding at the marches in Lahore and Islamabad. But the flag seen in the photo is actually the flag of Women Democratic Movement (WDF) -- a woman rights organisation whose members are among the organisers of the Aurat March.
https://twitter.com/wdf_pk/status/1369541740437385216?s=20
However, detractors of the march cannot be expected to do a Google search to find out the truth. They have been forwarding the hateful posts asking why Aurat March supported France where blasphemous caricatures were recently made -- thus accusing the marchers of blasphemy as well.
Our advise to the haters is to do some research before you go on your usual hateful spree so you don't end up looking like a fool.