The two genders
I think Tacy nailed the story semantic aspects of that subplot. However, I believe there's a larger thematic significance to Mama's mental episodes that never gets discussed. It's a much longer discussion about Big Mom, Sanji, Katakuri, Pudding and familial ties in One Piece. It'd be a very long write up if I actually wanted to give my full thoughts on it lol
Also I'd need to re-read some portions of the story. I mentioned a potential Katakuri character analysis in passing when I made the thread about Oden and the flow of time theme
https://bit.ly/2zGJctQ, Mama's mental episodes would've been a big portion of that write up.