I did some pointless but fun detective work regarding this artist.
I have long suspected this artist is the same person as Yururi Nano. Yururi left Twitter a while back, saying that if she decided to return someday, she'd go by a different name (see post #3222221). Around the same time, her best friend Natsune Ilasuto also left Twitter, and art from both of them stopped completely for quite some time. About 4 months later, Kizitora Hato appears, drawing pictures in a strikingly similar art style as Yururi's, but with a much greater level of polish. One of the first things they did was announce a new doujin circle named AsterMist, whose other member is an artist whose style greatly resembles Natsune's. https://twitter.com/oohashi_hato/status/1080373145284964352
Much more recently, Natsune reappeared on Twitter on a new URL (https://twitter.com/jajaneko_irst ), and unlike Kizitora, her Twitter bio links to the same URL as her old Pixiv account, confirming they're the same person. One of the first people she appears to have followed on her new Twitter account is Kizitora, and she retweeted Kizitora's new circle announcement tweet, seemingly confirming that she is the other member of this circle (she has additionally posted the same art on her Pixiv, confirming it's her once and for all).
-Note the similar eyes and repeated use of this exact mouth shape in post #3072300, post #2983816, post #3222210 and others. post #2798483 additionally contains the same use of "je" as a diminutive form of "ze" -- Yururi isn't the only one to do this, but she made this a thing she did in conversation at one point.
-ReiMari shipping happens just as religiously and in nearly identical ways (post #2866387 / post #3399830)
As one of Yururi's biggest fans, I'd be overjoyed if this really was her. Either way, I believe we should respect her desire to distance herself from her old name, but if I'm right, I'm also really glad to have found her again, and I'm heartened to see that she never stopped doing what she loved.