It depends on the type of makeup that she wears. Skin and hair lose pigment as we age, so it makes sense for a woman to use makeup that adds color her complexion. The trick is to avoid makeup that accentuates lines, sagging or enlarged pores. This means carefully selecting foundations, powders and concealers: Try them out before making a full-size purchase. It also means learning good application techniques such as using cosmetic sponges to blend and smooth foundation on the skin. Shiny makeup, along with bright colors, aren't good options for aging skin because they can look unnatural and, in the case of "shine," further accentuate lines, etc.
In addition to adding color to the skin with the use of foundations, tinted moisturizers, bronzer and/or blush, I also advise enhancing eyes with the use of a high-quality mascara (lashes thin with age, as well), particularly since mascara frames eyes without looking as heavy or obvious as eyeliner. Likewise, lip color is also important, as lips can become noticeably pale with age. My trick is to use a highly pigmented color my lips then blotting it and applying a coat of a lighter shade of lip gloss. This keeps the color on my lips while also giving them a bit of shine.