Following @prokhozhyj 's comment you could make two separate entries with a note saying female (with a red line pointing to it) and that the male is in a separate photo. Then do the same for that one.
As has been said, you have to judge how much effort you want to put into it. I wouldn’t do that - perhaps a comment saying mating pair. I do a lot of identification, and find that most observations do not have any annotations at all. Sex is rarely checked, partly because I work with moths and it’s really hard to tell!