|Fig. 1: 主「ナニサ|
"What are you talking about? I'm in no position to hide anything (fig. 1). This [place] is exactly what it looks like, so carefully examine it, if you want (fig. 2)."
|Fig. 2: 此姿|
Also keep in mind the unusual kuzushiji choice for 「す」 of 「春」, which we saw once before (fig. 5).
Edit: As explained by Matt in a comment below, 「どこ」 in fig. 1 is an abbreviated version of 「どころ」. Both mean "to be in the position", a pattern that was encountered previously (fig. 2).
Edit: The use of 「だ」 is likely analogous to possessive particle 「の」, as suggested by yudantaiteki. Although in modern Japanese, 「だ」 is never used in this situation, it certainly could have been during the Edo period.
Edit 2: also from that same comment by yudantaiteki, 「ものを」 can be interpreted as here as 「だから」 (see meaning 1.2 here).
|Fig. 3: 其子の|
"Regardless of what that girl said, she didn't know what she was [talking] about (fig. 3)."Once again, we see the unusual kanji 「咄」, something that surfaced in the past (fig. 4), for 「はなし」. However, unlike that previous occurrence, 「し」 is okurigana and not part of the kanji's reading, another example of irregular okurigana rules during the Edo period.
As for 「知れ」, 「も」 is a bound particle that, when it is preceded by a verb, is preceded by that verb's continuative form （連用形）. The verb 「知る」 can be either a yodan verb with ra-conjugation or a shimo-nidan verb; in this case, it must have the shimo-nidan conjugation, since only that one has 「知れ」 for its continuative form.
Edit: as explained by Matt in the comments below, 「知れもしねへ」 is likely a dialectal/archaic form of 「知りもしない」, or "not even know (x)".
|Fig. 4: マアそり|
"Well, that's that (fig. 4). How are things at your house? (fig. 5)," Tanjirou asked.
|Fig. 5: 宅のよふす|
Also interesting is the use of 「の」 as the interrogative particle (notably written with katakana here), something that hasn't been seen before in Umegoyomi.
Finally, something I picked up on here is that there are no periods at the end of a character's lines (i.e., when another person starts speaking immediately afterwards). This suggests that the use of periods in Umegoyomi was not to indicate the end of sentences, but to separate them. There would have been no need to include a period at the end of fig. 5, since Yonehachi's name would have appeared in the top right corner of the next sentence, indicating that she was talking now anyway.