Well, in order to make your skin look lighter, you'll need lighter shades of foundation and concealer. Brands like Ben Nye, Kryolan, Mehron, and Graftobian all have the palest of shades. If you want something of a glow, I'd recommend powder. If you've got the money, Hourglass just released a range of illuminating pressed powders. Otherwise, Aromaleigh
has some nice ones that are available in sample sizes. Also, NYX Mosaic Powder in "Highlighter" is a nice luminescent shade, which will give you an ethereal glow. Apply these to the high points of the face, rather than all over.
Finally, her lips appear lilac. Both Shiro Cosmetics and Fyrrinae has lip products in that shade, which are also available in smaller sizes ($2 or less). You can also check the drugstore and see which brands offer that shade of purple lip product.
In all honesty, it's not important for a cosplayer and their character to have a matching skin tone. I wouldn't sweat it.