I always get asked if I know bloggers/Instagrammers who cover the teen and above years
I don't think there are that many, if any. I haven't come across any that are specifically about parenting teens, probably because (having some myself) I know they would rather die than have me post anything about them on SM, let alone a photo of them.
I know you've stopped putting your eldest on your IG as much, but I'm really uncomfortable with the amount of exposure some of the kids in the Insta families get, for all sorts of reasons.