Oh I just came up with a wild theory
Which is the nonna didn't die, she was depressed so she moved out of the country and then rumors started that she died.
And she is really alive and she is that bold girl crushing on him
I thought earlier that she looks like our nonna but I thought that the author must have just made her like that or it was just an art style
but now I think nonna came back wearing yellow contact lenses, and blond hair with a new haircut.
I just have a gut feeling that I am right