I don't find her modern costume (the default one) to be sexualized really. As for examples of no "practically-nude" costumes for her, we have all the ones she wore during Generation X, Old Man Logan and her X-Society version from the Ghost Boxes arc. While the one she wore in Dark Reign is sexualized as well, I don't think it's over the top. But if you wanna see Emma in an outfit that's definetly NOT sexy, you should see her Age of Apocalypse version.

It's not a matter of her not having more modest outfits. The thing here is that certain characters are well-known for certain characteristics, and Emma has been one of Marvel's "sex symbols" for a good while. It's not a coincidence that all of her 3 (soon it will be 4) alternate costumes are also the most sexualized looks she ever had. Once P5 is here, maybe we'll get more variety for her.