“Can’t we just do this during the constitutional convention?”
No, because thus far no state has requested a constitutional convention to address gender equality.
A constitutional amendment can be proposed either by Congress or by constitutional convention.
A constitutional convention is called when two-thirds (34) of the states agree to gather. Although there is a current effort to call a constitutional convention, gender equality is not a listed topic. (source, Center of Budget and Policy Priorities)
Any amendment(s) approved by constitutional convention must nonetheless be approved by three-fourths (38) of the states.
The fastest way to constitutional gender equality in America is to recognize the 28th Amendment (Equal Rights) since it has already been passed by a two-thirds vote in both houses of Congress and ratified by three-fourths (38) of the states as required by Article V of the Constitution.