Should accept the sentence without "the"
No because it still has to make sense in English too.
I put 'an' instead of 'the', which probably should have been accepted
That's one specific child, probably needs a "one" in finnish for that to translate.
It's no more or less specific than 'the'. Normally when the article isn't specified in the source language they allow either in the translation
That's right, my bad. "the" is more specific to one single child. Yeah it probably should be right.