Girls around age ten may become interested in makeup.  Girls who watch their mothers apply makeup may want to try it even as little kids.  There is nothing wrong with adding a bit of color on the lips, and some lip balms and lipsticks offer sunblock protection as well as keeping the lips moisturized and healthy looking.

Opponents of young girls using makeup state that it makes them appear older and may attract the wrong sorts of persons.  My answer to this is that when you eat your picnic lunch in the great outdoors your sandwich may attract flies, but this does not reflect on the healthfulness of your lunch.  It is good for girls to experience a rite of feminine identity, and to feel themselves pretty.  Applying makeup can boost self-esteem, and the practice is more artistry than mischief.  The more we fuss and spunk at them about it, the more determined they may become to wear it at a later time.  Much better to give them a little bit now and to promise more as time (and responsible behavior) proceeds.

The best first makeup kit should include some very light powder.  Girls can be shown how to minimize blemishes with it (unfortunately some preteens will begin to get them). A very light shade of blush will also get them started nicely, along with some lip gloss or lipstick in a very pretty color (nothing brash or gaudy, and not just because they're young: that sort of stuff can ruin anyone's looks!).  Eyeliner pencils are nice, so long as they know how to use them without injuring the eye.  Mascara, on the other hand, tends to weep and smudge, so I would hold off on that until they're older.