Translation:I will collect the children later and we will eat chocolate.
In isolation and without further context, I think "gather" is a possibility. I would say that "gather" would imply the children were dispersed to some extent eg if they were out playing in various parts of a park and you were going to bring them together later. "assemble" might also be valid. I think the idea in this case (based on a similar sentence in the course) may be to go and pick up the kids (eg from school). With that in mind, I think "fetch", "get" (or even "pick up" or "go for") could also be valid translations, in real-world contexts, if not in DL. Sin mo thuairim phearsanta ach ní saineolaí mé, ar chor ar bith!