Edit: added previous context
Maruko has just asked grandad if he would save her from a wild dog. Grandad is scared but doesn't want to say 'no' to Maruko.
I thought my problem was only with the last sentence, but now I'm confused about who said the penultimate sentence too.
「まる子、おじいちゃんを混乱させるのはおよしなさい」
Mum: Maruko, please stop confusing grandad
「でもおじいちゃんの意見をききたいんだもん」
Maruko: But I want to hear grandad's opinions
見ると、友蔵(grandad)は「わしは...わしは...」とうなだれた姿で、さらに深みに入りこんでいた。
Narrator: When she saw the figure of grandad hanging his head and saying "I..I..." she probed more deeply. (who is she?)
「こらっ、もういいの。おじいちゃん、もう考え込まないでくださいよ」
??: Hey! Enough of this! Think harder.
質問をしただけなのに、おかあさんに「こらっ」なんて怒られる筋合いはないとまる子が思った瞬間、おばあさんがとりなすように言った。
Narrator: Even though it was just a question, the moment Maruko thought that there was no reason to get scolded by mum for saying a thing like こらっ, grandma intervened.
This is my translation attempt. I have two problems:
1) The なんて particle seems to cover a multitude of confusion here. For starters I guess it's replacing the quote particle と and there's an implied 言う. But secondly, it must be replacing something that gives the meaning of 'for'. I can't fill in the blanks here because I don't know how to say 'get scolded for a given reason'.
2) It isn't logically consistent. If Maruko didn't see a reason to be scolded why did grandma need to intervene?