Funny how you should ask me that, cause I'm in the middle of writing some kind of SF6 fanfic that deals with Chun-Li and her dealing with a grown up Li-Fen who wants to hang out with her own friends and have her own fun. And the idea of Li-Fen acknowledging Chun-Li as a "mom" is a driving factor for one of the conflicts. (DM me, and I'd be more than happy to share).
Now don't quote me on this, because I was never adopted like Li-Fen was. So I can't speak for everyone's experience on when they start calling them "mom" instead of their first name. I imagine some its instantaneous, others might take a little while.
Now remember that Chun-Li's character story in SFV does take place post-SFV. She rescued Li-Fen and adopts her right afterwards. And it's only been a week since the incident. As confirmed by the first line in her story mode: "A week's gone by since we started living together. It seems like she's gotten used to being here. But sometimes she looks so sad that I worry."
Even after a week, Li-Fen was still addressing Chun-Li as Chun-Li. Now, maybe they haven't filed the proper paperwork yet. Maybe they wanted to see if Li-Fen had any other living relatives before Chun-Li became a permanent guardian. Maybe Li-Fen was still too traumatized by the thought of being kidnapped and potentially losing the family she had before then. It's been a week, but a week is still very early.
As of right now, we don't know if Li-fen has gotten comfortable with calling Chun-Li "mom". They obviously have a very special and close relationship. She's been stuck with Chun since ASF. But would Li-Fen be comfortable calling Chun-Li "mom"? It is very possible. We don't have much in regards to dialogue between them. But the fact that Li-fen remains as her most important attachment to her life would suggest a deeper bond.
If you want a solid answer from me, I'd say that Li-Fen 100% acknowledges Chun-Li as her mother or even guardian. I do think Li-Fen would absolutely be comfortable calling Chun-Li "mom", but I think she'll address Chun-Li by name. Maybe that's the relationship they've had for since they've lived together. And if it's comfortable for them just to address them by first name, then that's fine too.
I do think Li-Fen would call her "mom" or have it slip out every now and then. Or maybe as a fun sarcastic remark.
Chun-Li: Li-Fen, what did I tell you about eating crepes before dinner?
Li-Fen: Sorry, mom...
Hope this helps.
I want all of those Chun-Li covers! https://store.udonentertainment.com/blogs/news/street-fighter-6-comes-to-comics-every-week-in-may-cover-creative-teams-reveal
