No, this isn’t typical. A 10-year-old student should spend about 30 minutes doing homework each night. You’re exhausting yourself and your student. Students are expected to be able to perform most homework unassisted. You and your husband are providing the in-depth help he should be getting at school.
If he is having difficulty focusing at home, he is most likely having difficulty focusing at school as well. He is probably not grasping the material, which is why he needs so much help with his homework. Have a meeting with his teacher and tell her that you want to have your son tested for Attention Deficit Disorder (ADHD/ADD).
If testing reveals ADHD/ADD, then an Individualized Education Plan (IEP) is the next step in getting your son the appropriate services and modifications that he needs to perform independently in the classroom and during homework sessions.
Your sister’s child has an IEP because he was evaluated and qualifies for special education services. Although it is true that all students would benefit from an Individualized Education Plan, the school is only required to provide those services to students with specific learning deficits.