It's not based on height but weight.
Peach is taller than Mario but are you gonna say she weights more than Mario?
Exactly, that's my point.
People say Rosalina can't actually be heavy and that she's only heavyweight because she's tall. Usually citing King Boo as "evidence" (being a ghost, he logically shouldn't weigh anything).
However, King Boo is an isolated case. Like you pointed out yourself, Peach is way taller than Mario, but is skinny and petite while Mario is chubby, so obviously she's lighter.
However, Rosalina is thicker, and has muscle. Plus, she isn't just "kinda tall" or something, she's literally a mini-giantess. She'd easily be heavier than even Wario, going by actual logic.
How do you even fit Mario canon together though? Seems all jumbled up and stuff though I do remember reading this one theory that put together all the Mario games and the spinoffs together which I found to be pretty impressive.
It's more from a "understanding the characters" standpoint that I care about Mario canon. Specifically with Rosalina, because she's misinterpreted to an obnoxious degree.
But as far as time line goes, some games easily link up. As in, it's staring you right in the face.
For example, Super Mario Bros, Super Mario World, Super Mario 64, and Super Mario Sunshine, all happen in that order. In Sunshine, FLUDD displays video footage of the former three games, based on data it has on Mario. Luigi's Mansion is canon too since FLUDD was made by Professor E.Gadd, who debuted in Luigi's Mansion. The Galaxy games definitely take place after Sunshine, because Pianta's exist in Galaxy 2. Most people believe Galaxy 2 is a "reboot" of Galaxy 1, but it's actually a direct sequel, as Galaxy 1's secret ending naturally sets up for Galaxy 2, and Rosalina remembers Mario, and references the events of Galaxy 1 in Galaxy 2's ending.
Also, Captain Toad: Treasure Tracker is a blatant prequel to 3D World.
I could go on but that's the gist of the most important games.