Laura sounded mostly fine in MK8. If you want to talk class, she literally says "Ta-Ta" when she passes opponents sometimes. She also says that in 3D World when she leaves a multiplayer party. I don't think Laura sounded too girly in MK8, she just sounded more energetic, which is fine because MK8 is a more energetic game, and Rosalina IS a gearhead, so she gets a kick out of racing in fast vehicles.
Mercedes actually had quite a few high pitched or "girly" voice clips in both Galaxy and MKWii.
In fact, the very first voice clip from Rosalina in Galaxy, is probably the highest pitched clip she has ever had (it's this really drawn out "ooooooooooh..." and it, quite frankly, sounds like a sexual moan - I actually think Mercedes Rose had a few voice clips that went into that "unintentionally sexual" territory). She also has a little giggle in Galaxy sometimes that sounds like it's coming from a five year old. Not to mention "Go Luigi!" in the Luigi playthrough. And she had plenty of weee's and wooo's in MKWii.
In actuality, ALL of Rosalina's voice actresses are terribly inconsistent, I could give you both amazing and bad voice clips from all of them. None of them are better than the other (though they all have a slightly different flavour, so it's fine if you have a favourite), as they are all inconsistent. They all sound really off when they do badly (Mercedes sounds like she's having sex or she's a five year old when she performs badly, Kerri Kane sounds like a smoker or an obvious ****** when she performs badly, and Laura sounds far too girly and preppy when she performs badly). But they all nail the character on their better clips, while still giving her a unique flair that helps you tell them apart (Mercedes makes her a bit more beautiful and wise than the other two, Kerri makes her a bit cuter and sweeter than the other two without sounding too girly, and Laura sounds a little tougher and tastefully sexier and sassier than the other two).
I want Laura to be kept for a while though, if only because I think she will develop a more consistent portrayal for her, something Mercedes and Kerri never got to do. Most of the other Mario characters have had the same voice actors for years, which has led to them having a really consistent portrayal that rarely sounds off, if ever. They always sound exactly as you would expect. With Rosalina though, none of her voice actresses have been able to get a handle on her for more than a session or two, meaning none of them have gotten a chance to really perfect their performance (and I know I'll get hate for saying Mercedes is flawed, but seriously, she isn't as great as people make her out to be). There's also the fact Nintendo has been going from Kerri to Laura and back to Kerri and back to Laura lately, which is just really confusing for people. Not to mention that instance of them crediting Kerri Kane in Mario Party 10, when it was Laura who did the voice.
It's because of this that I don't really have a favourite of the three anymore (MAYBE Laura by virtue of the fact she's the most consistent IMO - I only have a problem with her in MP10, and it's not all of her voice clips). I think they all need some work. My favourite performances for the three though, are Galaxy 2 for Mercedes, Smash for Kerri, and 3D World for Laura.
And I'm only posting this since my opinion on the three has changed quite a bit since last time I talked about it. Not looking for an argument, since I know most people here are set in their ways on what they think of the three anyway, and won't change their already existing impressions.
EDIT: So Rosalina once again features on the main menu for a game. She's on the icon for the main Amiibo mode in this game.
Just a random ditty. Always nice to see the bae on the front page of the game menu.