About Yamato, from what I read in the last couple of pages, i think what most of you guys are forgetting is that she spent ~20 years of her life pretty much alone, with the only thought of carrying Oden's will in order to survive...
Imo while it may have started as fanboying when she was young (dont most kids want to become like their superhero?), it eventually became the only thing she could hold on for so long. Fastforward to last chapter, she JUST learnt that the scabbards and Momo are alive, so her whole world must be falling apart. I think she cant process straight the situation, and is just confused af about who she is supposed to be now.
Yes it sounds stupid for her to call Momo her child but what, you guys think she can just instantly drop her roleplay only coz Luffy said it's weird? Nah, she needs an electroshock like Momo and the scabbards themselves telling her to fuck off