I could have totally written this post. I am homeschooling a 4th grader and a 1st grader. My kids are super laid back. They get excited about their own passions, but don't devour college level textbooks. Unless perhaps it's about the obsession du jour.
One thing that has helped with denial on my oldest is having achievement testing done twice. He's also taken the SCAT. His scores have been very high. He's also doing algebra as a 4th grader, despite me kind of dragging my heels. I was dragging my heels because I really felt his patience, interest, and writing skills weren't ready for real, rigorous algebra even though conceptually he had been there for a while.
I try to balance with my kids. My 1st grader is challenged very little academically at the moment - I'm trying to compact some things for her so she can be more challenged by fall perhaps. But she's a young first grade and she is being challenged daily by extracurricular things like violin lessons. My 4th grader does 30-45 minutes a day of math and if that means it takes a week to get through a section in his Algebra curriculum, so be it. My kids do get frustrated very easily. But they also are so happy with themselves when they figure out something new. I think overcoming that perfectionism/laziness is a marathon not a sprint, and I've seen quite a bit of progress with my 4th grader in this area now that we're into our 3rd year of homeschooling. You can start with challenging her academically just a few minutes at a time and go from there. I wouldn't panic - 7 is still very young! And if you can afford some open ended achievement testing that can be very helpful as a baseline. We had the Peabody K-12 oral achievement done in our house for $55.
