Reading this chapter a second time... I noticed a few things (there were fewer tears this time around).
A bit subtle but actually very powerful: Miwa's mother doesn't react very quickly. She's a very thoughtful person. She didn't do anything when she heard Akane's name for the first time, and she barely said anything when Miwa dropped the bombshell about her infertility. When she finally did speak, she had all her ducks in their proper rows: regardless of whether or not she understood Akane's situation, she accepted it as being good for both An and Miwa (and that that was the most important thing), and though she still wanted grandchildren, that desire - that tradition that she undoubtedly has been taught and clinging to all her life - paled in comparison to the love she had for her daughter. She got (admittedly shocking) news, took the time to process it, and got to a healthy place. That demonstrates the sort of maturity that we should all strive for.
A blink-and-you-miss-it moment: throughout the previous chapters, we see Miwa, Akane, even An stealing glances at other people: couples in love, families with children... people who are living the sort of "normal" lives that they all want but can't have. Here, when Miwa and her mom are sitting on the bench, we see a Miwa's mom take a turn: she sees the happy families out and about, which include grandparents and their grandchildren. I feel like these moments are very poignant. Comparing them to 'The Wizard of Oz': recall that the Scarecrow bemoaned his "head all full of stuffing" and desired a brain; recall also that he was the one who tricked the apple trees into throwing their apples, thus providing Dorothy a meal. Recall that the Tin Woodsman desired a heart, and yet, he was the kindest and most soft-spoken of them all, and always the first to come to their aid. Recall that the Cowardly Lion desired courage, and - albeit with a little help - confronted both the Wizard of Oz and the Wicked Witch of the West. Just like Dorothy and the slippers, these three had what they wanted all along: they just didn't realize it. Miwa, Akane, An... and now Miwa's mother... in a very meaningful way, they have what they want. It's messy - real life often is - but ... they have it. And I think Miwa's mother seeing those happy families at the zoo is a way to show us that she is now on the same path as the other three: the yellow brick road that leads them to realizing they had their way home all along.
And I know it's a bit more on the nose but I can finally see this panel without tears in my eyes so I wanted to shout it out: the last panel in the chapter, showing the happy family, and Miwa's mother saying "that face is more like it". In context she's talking about Miwa, having previously bemoaned the other picture of them at the zoo. But comparing that one to this newer one... well, Miwa is definitely her old self again, so there's that. But I'm sure Miwa's mother remembers what An (and Shiori) looked like when they suffered their traumatic moments, and seeing An with that big smile on her face... ... but then you have the other one: Akane. This may very well be the first time Miwa's mother has seen Akane as her true self. ... "That face is more like it". 'Nuff said.
Hokay, sorry about the rant. Just needed to get that out of my system. Looking forward to the next chapter <3