A guy coming into shul early for shachris, can ask a woman coming in the same time to put down a sefer or a coat on one or two seatsin the ezras nahsim for his wife or daughter(s) who are coming later. However, as I’ve indicated in other threads on the same topic, I find this whole minhag of “saving seats” offensive, on EITHER side of the mechitza. The worse examples are on the yamim noraim, where some ehrliche yidden put down tallesim across an entire row reserving 4, 5 or 6 seats for family members arriving later.