Hi R.- My mother introduced tampons to us right after we started our periods. Pads were just so gross and messy, and hard to keep a girl fresh and clean, especially in Jr. High.
I reccommend using a product called insteads. You can get them at the drug store. Target used to carry them, but it's hit and miss. Anyway, you cannot get TSS from them, and they warm and soften and shape to the inside of your body.
If your girls are going to use tampons, start with the smallest or light flow and don't go above the medium ones until they can read their own body's signs. Mine, for example, actually pushes the tampons out when the flow is too low for what I have in their. Gross, I know, but you can actually start to feel ill when you have the wrong one in their, and removing it clears everything up. I actually alternate between kotex pads (they are cotton, not plastic like always, and they are much softer and less odorous), tampons, and insteads. It just depends on how your body is doing. I also reccommend that if they drink soda, they stop, if they eat alot of junk food, they really watch their intake.
Brighter, thinner blood is a sign of a healthy body and a healthy period. They are usually shorter, too. I notice about how I feel and can actively compare it to my diet and my period. Just things to keep in mind.
As far as age, I was 11 when I started my period, and tampons were just the fix. I used them on my second period. My sister, however, did not like them for the longest time and used pads until she was in her late teens.
Buy small boxes, see what they prefer. Ob's are kind of messy, but work great. The cardboard applicators- you have to be pretty smooth with those, and the plastic applicators- I find that brand doesn't always matter, but the ones with the thinner "handle" are easier to insert while the ones that are "one size" on the handle have more absorbency and more cottom.
I hope this helps
Good luck
And don't be afraid to be bold and blunt with your girls about the ups and downs. If it's not a big deal to you, it'll just be another feminine issue to cover.
Last thought, about the diet, etc., I have noticed that my PMS is far less and I am able to get a handly on myself. The cramps are not any better or worse, but my mental state is. =)
-E. M