I watched the scene in question just to make sure on everything. Littlefoot and his grandparents were talking about how it would have been good for Littlefoot's mother to have given him a brother. Counting every single word uttered that mentioned her, there were 4 references (words like her, she, etc.). Plus, there is the issue of the proportion of the cloud. It was obviously a play on the brother thing, however, the fact that it is similar to a scene from the original movie cannot be ignored. I think that it trying to be both. Possibly the brother alone, but not the mother alone.