This isn’t unusual but it remains taboo to talk about. You could tell her during sex how much of a turn on it is for you to smell her. Or if you prefer unwashed genitals for sex and she usually washes to reassure her she doesn't have to bathe before sex, as you like as she is. It may be both of you find this awkward because we’re so used to being told unwashed/unscented genitals and sex don’t go together. But she may be reassured that you enjoy how she looks, tastes and smells. It remains her choice about whether she wants to wash or not and she may struggle to relax and enjoy sex without washing first given it’s so ingrained in our sexual scripts.