Preteens or ''tweens' (ages 8 - 12) will have different skincare needs to younger kids. Puberty often brings oily skin and/or acne, so a foaming facial cleanser containing witch hazel may be helpful - try Sukin Foaming Facial Cleanser, $12 for 125ml, or Natural Instinct Foaming Facial Cleanser, also $12 for 125ml.
This is nothing to with skincare or anything - but, if you want your daughter to use more natural menstrual products, check out Natracare. They make enviromentally friendly menstrual products - their tampons are made from organic cotton - and their website is pretty cool - check it out at http://www.natracare.com/ It has a lot of really interesting info on it.
For girls who are just starting to get interested in makeup, suggest they try a glossy lip balm like Living Nature Lip Balm, $16 for 10ml, or a tinted lip balm like Alba Botanica Terratints, $8.99 for 4.2g.