Honestly, they all wean!
No-one breastfeeds into highschool.
Mostly, mothers who breastfeed the longest have the most kids. We are designed to breastfeed, and for that reason, breastfeeding is *easy* on our bodies. It actually doesn't *take it out of us* - that's western mythology. Your body is alreay replenishing as your baby takes less feeds- to be honest, if you eat well, as most mothers in the west do, you don't need to replenish - you do that naturally.- your body is more efficient in taking up nutrients from the food you are eating. Many women go from breastfeeding to pregnancy wihout missing a beat - no period, and baby weans as the placental hormones dampen down lactation.
You have breastfed long and well, so wean if you want, but don't worry that if you don't you will never wean, or that you have to wean to get pregnant