Yes, an 18 year old can be in homeschooling. In most states, the legal age for compulsory school attendance is 16 or 17, meaning that an 18 year old is no longer required to attend school. However, some parents choose to continue homeschooling their children beyond the age of 18 for various reasons, such as to provide a more individualized education or to allow their children to continue living at home while they attend college or trade school.
It is important to note that homeschooling laws vary from state to state, so parents should check with their local school district or state homeschooling association to learn about the specific requirements for homeschooling an 18 year old.