Here is the sentence I mentioned.
ほう その良家のおじょうさまたちだけがなぜ 肉親もおらん少年院に入れるんす？
I have 3 questions relating to it.
Is it a short colloquial form of 「ですか？」?
Does the word 「なぜ」, in this sentence, mean 'why'? If not, what is the purpose of it in this case?
Can I translate it as 'Hey, that is just a group of daughters from noble family which is the reason why they can get in to the reformed school, right? Please explain the reason to that point.'