They should put the chapter title clearer.. to know that this is the side story.. maybe they did but translator skip it? Idk...
There should have been chapters like this one that should have appeared waaay before this one, but I don`t remember reading them, so if they just posted this chapter randomly I think they should have posted the others too. If my memory does not fail me, I think that the author was writing 1 chapter about it every 5 or 10 chapters about the MC so that the main story would eventualy catch up clearing things up. So its no surprising that this one chapter is confusing. ╮(￣▽￣)╭
So, I thought I could clarify what is going on in the manga for those who haven`t read the novel (づ￣ ³￣)づ.In the novel, we kinda have a main and a side story, the first being the story of the MC and her struggles and the second, the story of the classmates who reincarnated into humans (but I dont think that part is shown in the manga? sry dont remember), and you should keep in mind that the timeline is different, while the MC is going crazy in the dugeon like place as a spider, her fellow classmates are growing at a human pace, still being babies by the time of the first chapters so they cant do anything much with their bodies. So, finally, chapters just like this recent one (Ch.29.2), happen in the future where those who reincarnated as humans have already grown up, while the MC as already had the time to do a lot of things until they`ve reached such age (Should be at least some 10 years in the future, I think, in this chapter), so you should treat these type of chapters as a sneak peek into the future.The "main" story features our spider MC and will eventualy catch up with the "side" story of the future so you can understand where the story is going, until then you won`t really get much of whats happening, but rather pick up the the missing factors as the MC grows.
With that said:
-Sorry for the spelling mistakes.
-Sorry for the lenght of this.
-Sorry if I spoiled something.
And I hope this helps. (〜￣△￣)〜