It would seem to me the sentence says "little sister makes cheese dokku (whatever that food is) and .. big brother ... ?
I can't understand 作ってみたら . Is みたら the tara conditional form of 見る? Is it another thing? By intuition I would guess he's trying to say that she makes the cheese dokku and he uploads it to internet (youtube) to be seen? perhaps? but I can't make literally sense of the phrase. If みたら is a verb in conditional form, which verb it is and how does it fit in the sentence?