Some kids are more mature and able to focus on the task at hand. Others need frequent reminders, and tend to drag their feet when asked to cooperate. As you can see, there are a lot of variables.
It is not unusual for homeschool families to have both parents working. What is unusual, however, is for both parents to work full-time. The families that do have a very strong commitment to homeschooling, and are willing to sacrifice to make homeschooling work for them.
I know of two homeschool parents, both psychologists, who stagger their clients early in the day and later in the evening so one parent is able to focus on the kids. Another father I know operates a mobile "office" from his car and works while his kids attend homeschool activities. And still another, a dancer, schedules her classes and performances around her daughter's homeschool calendar. So it's not impossible to homeschool and work full-time, but it is a challenge.
I've also known several families who took their work experience and training, and channeled it into new careers. A few started home-based businesses, while others provided services to families who learn at home. For more help and advice, please visit our How To Homeschool center.