I distinctly remember getting my first period at age 10 years 8 months, which was near the end of 5th grade for me. I don't remember when other puberty changes happened.
I was a *little* young to be dealing with everything, although some of that could be attributed to the fact that I was NOT prepared for womanhood. My mom avoided talking about it, left it for the schools to educate us. I was embarrassed to even go to her for menstrual supplies. I think if I'd had more emotional support through that time I wouldn't have felt so lost and scared.
Same here. Sexuality was just something not talked about in my house (unless the speaker was my step-father and Mom was out of earshot ) I vaguely knew what periods were somehow, so I wasn't TOO shocked when I started bleeding (didn't think I was wounded, sick, dying, whatever). But I was too embarrassed to tell my mom. We actually had some applicable sex ed before my second period came around (they even told a sad story about another girl who didn't tell her mom, her mom felt all betrayed and blah blah blah--Didn't get me to tell Mom, just made me wracked with guilt), but somehow I got through it without realizing that I had to worry about another period soon. Big shock when I bled much more noticeably next month, and classmates noticed before I did. (I remember some girls calling out and asking how old I was when I was obliviously walking to recess with bloody white shorts. They may have been the one to alert the playground aid lady, who escorted me to the nurse. She found me in the bathroom with toilet paper stuffed in my underpants AND held to the outside of my shorts, because I was hoping to hide it that way, LOL. Man, I cried so much on the way to the nurse. The good news is that the nurse told mom so I didn't have to!
My mom was (and probably still is) convinced that I didn't tell her because I thought she'd be mad. (I can't find the head-banging-on-wall smiley.) In her defense, the reason she didn't prepare me for my period was because she thought I wouldn't get it until 13 or 14 years old.
When I hear people objecting to sex ed in elementary school, I'm horrified! If I have daughters, I think I'll give them a little heads up when they turn 8, just to make sure they aren't too shocked when they're suddenly oozing blood. Even though they probably won't get their period until 11+, I figure there's no harm in knowing about it.
11 1/2 really wasn't too bad of an age, even with all the support I lacked. I'm surprised when people feel it's entirely too soon. It's not. Our kids will survive. LOL
I get the feeling many people are really resistant to girls growing up... or something. You see it in parents denying their girls control over their appearance, often with really strange justifications. Lots of moms on this site can tell you some depressing story about how their own mother wouldn't let them wear a bra, even when they really needed it. Another common one is that the girl isn't allowed to shave her legs, even when she clearly has terminus hair dark enough to embarrass her, because... shaving makes the hair grow in darker! (head + wall) A recent topic had a mom saying she didn't want her daughter having earrings or nail polish because she didn't believe in sexualizing young girls. I once saw a really old topic where a mom felt that NOT wearing pantyhose made her daughter "look promiscuous." Same with make up, hair coloring....
In fact, even though my own mother was the sort to let us kids smoke and drink (in the safety of home!) and even buys my 13-year-old brother cigarettes, she forbade my 12-year-old sister from dying her hair black, because that's "too young" to have your hair dyed. When I press for an explanation, Mom said she didn't want Sister to destroy her hair so early with all those hair dye chemicals. (Because buying a wig or just going without hair is way harder than getting a lung transplant or just going without lungs, right?)
I'm pretty sure Mom would have held back our menarche if she'd had a way. (Which I wouldn't have minded, because periods are annoying, but my convenience would not have been her main motivation.)
Maybe most parents can't help to resist their kid growing up, and I'll understand it when I finally have my own babies. But... I haven't noticed as much of this for boys.