Once Princess Daisy debuted, not that many people knew who Princess Daisy was at the time. Back then, people couldn't take Princess Daisy very seriously because they had no idea that Daisy was not Princess Peach during her early years. The line "This is all Daisy has." tells me that Peach feels sad for Daisy having her only retro appearance be Super Mario Land and not that many people including Nintendo could take Princess Daisy very seriously back in the 90's. I like how Daisy is putting sense to Peach and 90's gamers alike.
She was never intended to be a clone, and she never was a Peach clone to begin with. Not that many people take Daisy very seriously, and they never do. I hate it! I know that Daisy is a joke character, and has a loud voice, but she's not a joke. Daisy is not a Peach clone, but not even Nintendo would understand that, and not even 90's gamers back then. To be fair, Princess Daisy is more goofy and silly whereas Peach is cute and elegant. This is why I can't have nice things because some people don't take the odd ones out very seriously.
I don't like it too, but you have to understand that Daisy is jealous of Rosalina just because Rosalina got so much praise when she first appeared in Super Mario Galaxy whereas Daisy is treated as a joke being set aside to spin-off games. Daisy is jealous of Peach because Daisy got left behind during the 1990's just because she was accused of stealing Peach's identity since her old design was a carbon-copy of Princess Peach. In other words, 90's people outside of Japan were misunderstood about Daisy when she was new at the time because they weren't aware that Daisy first appeared in Super Mario Land. That means, they didn't know that Daisy wasn't Princess Peach because people back in the early 90's may have not played Super Mario Land. Dense as it is, that must be the case here.
"This is all she (Daisy) has."
I forget this is set before the reveal of Daisy being in Super Smash Bros Ultimate, as well as her recent inclusion in official Nintendo art, and her use in promotional materials for the Nintendo theme park. Hopefully the rumors about Super Mario 3D World Deluxe are true too.
But I wonder, will the news about Daisy getting into Super Smash Bros Ultimate play a part in this story by the end???