あなた should make this into a fanpick in the "Picks" section if あなた want to keep track of votes, but if あなた want a written opinions(s), i personally think Minnie in her original powers could pown any other child in the series as well as several adults
Truth be told when I say they already had a battle and Minnie and Jr. ended up getting stuck together when they were hammered down. But of course i was kind of confused during that time so I suppose it just couldve been minnie trying to keep Jr. close to her and out of trouble. but if i were to choose who would win honestly i think it would be Minnie because when it comes to Jr. she tends to resemble her mother when she gets angry for both jealousy and Jr. simply getting hurt.