Re: One line
this character speaks in funny way. may be she's too young that can't speak properly yet. the last bubble too she says お兄ちゃんをきゅうしつ but it supposed to お兄ちゃんを救出（きゅうしゅつ）.
i guess that's the problem of this ケガニのこうみょうツチューにカツ.
as the suggestions given by unproductive and the Vapour, this character means 怪我にの功名,死中に勝つ but this kid can't pronounce it properly or dont know the kanji of it. (i think the author want to make her cute by making her speech incorrect.)
what she mean to say is that since she is a little kid that's why they looked down on her and let her into this place easily.
referring to unexpected good consequence from a bad incident.
good consequence = got into the place without hassle.
bad incident = bad situation = being a little kid.
oh, one more! 怪我にの功名,死中に勝つ is actually, 怪我の功名,死中に勝つ (no に)
this is not a typo of the raw. many japanese kids find difficult to remember those phrases so they change a bit to make it easier to remember.
this kid used some name of the food so that she can remember it ^_^
