That scene with her tying her shoelaces felt downright uncomfortable. Wei Wei isn't a bad person, and she isn't some sort of sexual predator or anything. But dis girl is toooo yooooung for her, and she knows it. This isn't a love affair, it's Wei Wei having an early midlife crisis and shacking up with someone that she doesn't really have any true connection with. She's not in love, she's reliving past love.
For that matter it's not even clear that the girl is actually in love with her either, it seems like she's at least partly seeking an escape from her home, although we don't know why yet.
Like, this story is about a relationship between two people, but so far I don't think it's really correct to call it a romance. We're not really supposed to be cheering on this relationship, even though we can root for both of the characters the story keeps pointing out all the ways in which this is totally not a healthy relationship.
There's some force to this, but I think what makes it a good story is that it isn't entirely true. For Wei Wei--sure, it is a crisis (although she's still too young for it to be "mid-life"), and yes, she's reaching for something in that girl that isn't entirely about her as an individual. And yet at the same time, it is a love affair, and there are individual things about that particular girl that do attract her and hit her emotions--things she does, things she says, things she is. It's not an either-or, it's a both-and, on a sliding scale. In fact, I would say the big question the whole story is working on answering is just where on that scale is the relationship, and where on that scale will it end up?
(Also, I really don't think she's reliving past love. To the contrary, she's trying to exorcise past love)
And the same is true for the girl. Sure, she's reaching out for someone because her life sucks and she feels abandoned and lonely. Well, and don't we all. But is she reaching out for just anyone? Could she, would she have fallen for no matter who? Surely not. So just where is she on the scale between "one true soulmate" and "any port in a storm"?
Finally, there's one more question--so, say for both of them they've sought each other out to try to fill deep emotional needs and heal major emotional pain, and so they're using each other. OK, so this is not very romantic, and one might even say "not healthy", but what does that "not healthy" mean? Does it mean they'd be better off not filling those needs or healing those pains? They may still both be better off with each other than without, especially as long as they're reasonably generous and caring about the whole thing. Would that girl really be happier going back to her dark room?