I don't think this is a historically accurate ending in any way. I think the idea that Hanako becomes an author to share her lost love is likely much closer to what would have actually happened sadly. For anyone that wants more bittersweet historical yuri, I highly recommend Moonlight Flowers by...
There really aren't happy same sex love stories set in this time period as a rule. It's simply true to life unfortunately. For a much more modern but still historical yuri manga set in Japan, consider Moonlight Flowers. It shows a somewhat realistic take on same sex love during the time the work...