Answer:
Not my sister nor my brother but still the child of my mother and father. Who am I?
Once you know it exists, it no longer exists. What is it?
What goes inside boots and outside shoes?
What has to be broken before you can use it?
A squiggly line tells you when you've done it wrong
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.