Hi housemad! I've just had a look at your thread on the primary board. Here's something that really jumps out at me from that: your child is already learning brilliantly, according to her own schedule rather than by following a straight-line trajectory as dictated by somebody else.
You can just see that. You don't have to mark work objectively, nor do you need to check whether you have imparted the correct knowledge.
For example, you said "She loves writing so dc can seat at a table for a long time just writing out pages and pages even just dialogues from YouTube videos. I believe that's how she learn her writing and spellings more than in schools. As after the six weeks of summer holiday when she went back to school her literacy improved overwhelmingly and her spelling went up by 2 & a half years/ages."
What's to measure? You would have known she had learned huge amounts from her YouTube passion even if the school hadn't assessed her as making 2.5 years' progress in six weeks. During those school holidays, you didn't have to sit over her checking that she was doing the "right thing". If you had, she might have put down the pencil!
If you were climbing a Ben Nevis or writing a novel, you wouldn't need to keep calculating obsessively how many metres you had climbed in the last hour, or how many words you had written today. You'd know you were making progress. Sometimes it might feel like more progress than other times, but still you would be aware that you were going places. Education can be like that. Keep looking at your little girl rather than at the targets, and you'll see it happening before your eyes.
I know this is a bit hard to accept at first; there is such an obsession with levels and progress at school - how could you leave all that behind? But as you know, your child is not "typical" (what child is?) and she'll follow her own path. Over time you'll discover a sense for how she's developing and whether there is anything to worry about. There rarely is!