@Tych I'd assume it's not being axed, it's been fairly chill about the storyline so far and unpopular/axed manga tend to be a bit more abrupt.
It seems as you said to be a concept that doesn't have a long run time, especially since its focusing only on an arguably small cast and orbiting around big sis, her worries and her troubles while spicing it up with cooking and cool beasties. (but repetitive formats usually have that issue)
Though it'd be neat if it went on for at least a few more chapters. I need more cute jade faces in my mental library lol.