It sounds like she’s doing really well, and it’s great that you enjoy fact books together. Can she read in her head? As
Legomania said, once they’re at this stage they realise that silent reading is faster than reading out loud. If she’s ready, perhaps you can see if she wants to read a couple of pages of her book silently to herself, and then tell you what it was all about. Not that this is a substitute for reading out loud, of course!
How is she with expression? If you do as SeedsSeedsSeeds says and read alternate pages with her, you can model reading with lots of expression. My DD would howl with laughter as I put on silly voices for different characters – and then she’d have a go herself.
Another thing you could do is read to her from a more challenging book, a few pages per day, so she looks forward to story time with you, without any pressure put on her to do any of the reading. Perhaps a bedtime story, if that works for your routine at home. That’s a great way to expand vocabulary and build stamina with following a more complex story, and of course it’s fun too, if you choose a great story.
Would she enjoy a magazine, puzzle book, wordsearch? Have you tried taking her to the library to choose books for herself?
Are there any opportunities where reading is the ‘default’ occupation? My DD fortunately doesn’t get car sick, so we always make sure she takes a book with her in the car. When there’s not much else to do, it’s easy to just read the book that’s on your lap! Similarly, whilst you’re at the hairdresser or she’s waiting around with you for something? Always have a book handy.
Regarding spelling, I think it’s pretty normal at that age to make mistakes and have to be encouraged to think about it more carefully. Have you tried using subtitles when your DD is watching TV? It embeds reading and spelling without them really realising it.
I definitely wouldn’t worry or push too hard though – it does sound like she’s doing well.