To me it felt like two friends just joking around. So maybe less sarcastic but just jokingly saying (sarcasm has a slight negative tone to it imo).
I believe this is after Jumbo says that Yanda isn’t coming and Dad says that’s fine, Jumbo can do the work of two men, so he’s saying like “well I’m not doing it (Yanda’s part).” Dad then says “please do the work” 働いてくれ。。。
Ahh! thank you! This makes sense - the classic case of not realising there is an implied object in the sentence (in this case, Yanda’s part of the work or double the amount of work, etc).
That makes a lot more sense! I took it too literally like dad was seriously injured, but they did just unload a whole truck after all! I think I’m trying to squeeze meaning out of every sentence and convinced myself there was something deeper going on…
Thank you both for the explanation! 
So not sure if this is normal or a dumb question. When I was reading, I had trouble with Yotsuba’s dialogue because there’s no kanji and I can’t tell where hiragana words begin and end too well. Does this get better? Is there something I should do? Even if it’s a word I know, it’s like I don’t recognize it in hiragana
I think this looks good! I’m not sure “by the way” would be the best way to translate なんだ, since Jumbo saying he likes pudding is part of the conversation, rather than a change in topic. A lot of sentence endings don’t have direct translations, it seems.
I’m also not sure the first line should be so directive - maybe more like “it seems I shouldn’t bring something weird.” I was having a hard time finding information on ーてくんな though.
This might be silly but have you tried reading it aloud? Sometimes that helps me figure out what’s supposed to be a verb vs a noun etc.
For me, it got easier when I understood which hiragana were acting as particles (these are hiragana that show the role of a word in a sentence). When you know which characters are the particles, it’s easier to tell when one word stops and the next one begins.
For example: ケンはケーキをかっている (Ken is buying a cake)
This is easier to see because there are a lot of katakana words. But は tells us that Ken is the topic of the sentence and を tells us the cake is the object or thing he is buying. The ている tells us that this is a verb that is continuing at the moment.
This is definitely easier to tell with kanji, though!
Page 13
な is from the adjective to attach it to んだ. んだ / んです / のです can be used to assert a reason for something. “I like pudding” is basically the statement, the んだ makes it declaring the statement as an explanation of what he likes receiving (as that’s already the subject).
I thought something like “I’m fond of pudding (when getting introduction gifts)”
The third line.. is a little more vague. Your translation isn’t really missing anything, but I took the いや as like a “Never mind, your tastes are good”
Ya, this is the problem with no kanji in Japanese. The love hate issue with them, lol. Basically, practice and get more familiar with things. Her text catches me when I don’t recognize something, but when the rest of the vocabulary and grammar make sense it gives boundaries to the spot that doesn’t look right.
For me, everything about the different sections of Japanese is kind of like this.. I used to hate having romaji on things because my eyes would drift to it as it was easier to read, and then furigana had the same issue. As kana and kanji have become easier I like having furigana now as it helps for the kanji I don’t know yet and the kanji I’m familiar with I can read without my attention being drawn to the furigana. Romaji is always a crime, but at least I can ignore it now and it shows up less outside beginner stuff.
Explanation
変な = weird
もん = thing
持ってくんな = 持っていく (bring something), んな is a slangy way to make it negative
よ = “command”, telling him not to bring something weird
俺は = I
プリンが = pudding
好き = liked by
なんだ = のだ, shortened to んだ, emphasizes or gives information, sometimes a command, overall similar to よ, MUST have な if it follows a noun/na adj instead of a verb. Overall, simply “I like pudding”.
いや = no (or bad, don’t want, don’t do that)
おまえの = your
嗜好 = taste
はいい = enough; いい technically means good, but it can be used just as in english when you say “No, I’m good”. は emphasizes that Jumbo’s taste, specifically, is something that we don’t need any of. はいい and いいです are commonly used for this “Not needed” meaning. So I interpret this one as “No need for your preferences”. Like, don’t bring pudding just because you like pudding.
Thanks for pointing that out. That’s cute how she’s parroting other grown-ups here. I’m starting to see her charm. And also an introduction (for me) to the ない内に grammar point.