Given that the same objections are raised on various instances every time only-flowers are sent on Women's Day (This year's German thread is currently at 8 pages of discussion) it seems useful to consider altering the gifts rather than shutting down the conversation.
Here are some examples of gifts on other days:
Women's Day has been the only set that's Purely Decorative, and while flowers are nice it really does seem to miss the point. Also worth noting is how a little thought regarding theme has been used for other days.
So, some quick suggestions:
Manuscript, Tools, Mother Tree Ritual Buff, Flowers
Manuscript, Coins, Employee of the Month Badge Buffs, Flowers
Flowers are a common gift in many countries, and they're nice to receive no matter one's chromosomes, but as the only item... That is a bit weird, even if kindly meant.