Puberty- I am not (emotionally) ready

The TL;DR bit is: 2 of my 3 kids seem to be showing the early signs of puberty & I'm feeling emotional about it, quite unexpectedly. Also: if anyone has recommendations on resources for them or me, I'd love to get some!!

I have 3 kids: son(9.5), Older Daughter (8), youngest (4). My son's pediatrician recently said that he was becoming prepubescent (changes in foreskin area were the sign) and last night my older daughter wanted to talk to me in private as she was about to get in the shower, because she'd been noticing discharge in her underwear and thought something was wrong. I also saw- only 1- dark & more coarse hair in her public area.

We've been over the basics of how bodies will change & periods and I'll be looking into some books and such for them & me to prepare....

but I am unexpectedly feeling emotional about this!! I am not ready! Right now I wish I could just keep them as they are & not have to worry about all the emotional turmoil & changes and all of the junk that comes with getting older. We're all Neuro-diverse, too, and I know from my personal life that it can make things harder- especially as you begin to get older- which is hard enough on its own. I just want to be able to shield them from the bad parts as long as I can.

And I also feel like I haven't had enough time with them... even though they're still going to be with me for years, I know they're going to soon be at the age where they want to be out with friends or whatever more than they want to be with me & things will change a lot. Logically, I know that it's part of life. I know there's not all bad experiences & that there's still likely to be closeness between us & that often (IME anyway) making it through a lot of the hard parts helps us grow as a person & that can lead to a lot of good parts.

But right now, I'm going to feel a bit sad that all of my babies aren't quite so little anymore. And I'm going to look into more resources to help us prepare for all the stuff to come.

If anyone has recommendations on anything- books, websites, whatever- for the kids or for parents I'd love if you shared the info!!