As someone who haven't read your story and only the synopsis—and doesn't mind having the occasional spoiler—what did you exactly do? Mind giving me a skeletal frame of what you did? Like, what was your storyline and how did you "move it too fast"? What "things" did you do?
As a generic question: It seems like—at a quick glance— a slice of life novel. What's the focus on? The relationship dynamic between the kid and the MC? If that's so, then your plot is never done. There is always something to write about with interacting with kids. You can even build a plot after your original plot. There's always room for growth. Or in Xanxia terms, there's always a heaven above the heavens.
For example: Kid was sent back to parents? Well, time to partyyyyy! Let's clean up the hous—oh? What's this? sigh. That kid left their favorite blanket behind? What to do?