My suggestion would be to remove Male.
Rearrange the tank. Making areas the smaller female can access but not the Male.
putting the female in first. Then after a few hours adding the male.
still a little risky
You could always buy a divider for the tank. Female on one side, male on the other... until the female was large enough to defend herself, that would take time. Maybe feed the male every other day and the female once a day...im not sure how u would like to do it