Well, I found the concept of her from Deviantart, I'll show you the picture.

And she's supposed to be using this version of the Vampire Killer as her main weapon, hope that helps give you an idea of how her whipping animation will look Belmont style.

Personally, I'd rather not have her design fiddled with too much. Maybe a
slightly more pronounced waist, but that'd be like it. Anything else would make her a bit too fanservicy I think. I don't want her to be overly womanly. That's kinda the problem with a lot of girls and women in today's games. They have something about them that makes them overly attractive. Like say Samus from the original Metroid for Nintendo. While sure you can play her in a leotard, it wasn't overly revealing or ridiculous because her figure was properly in proportion. There was nothing that attracted you're attention to a certain bodypart because she was so in proportion. Nowadays girls in games either have big chests or big butts.
So a slightly more womanly figure, but nothing over the top. Also keep the boots around the height that they are now. I've seen enough playable thighhigh or ankle boots on women for a good while.