I watched a documentary a while ago and I think it said that Kim Jong Un's sister plays a big part in maintaining the regime. I wonder if she pulled some string

I watched a documentary a while ago and I think it said that Kim Jong Un's sister plays a big part in maintaining the regime. I wonder if she pulled some strings in this decision to select Kim Ju Ae as heir, perhaps because she's more pliable, or under Kim Yo Jong's thumb. A North Korean patriarchal society probably wouldn't be amenable to a woman telling a male heir what to do.