You cannot be your childs buddy or best friend. And you shouldnt feel like you have to answer every personal question your child might ask you about your own life or history. Establishing boundaries for ourselves, the things we will and wont talk about with strangers, family, friends, and eventually romantic partners, is an important developmental stage, and you can model for your child by having clear boundaries about what you will and will not discuss with them. If you can be consistent with this, over time your child will learn how to develop and maintain their own healthy boundaries with others