4-year old reading level

Damn! I've been making Sofi read me her bedtime story the last few nights. (Negotiation goes like this: Sofi: I'm too tired, I don't wanna. Jamie: How about I read you first story and you read me second? Sofi: Ok. Later: Jamie: Ok, what are you going to read me? Sofi: I don't wanna. Jamie: But you promised! Etc.) Anyhow, she just made it through Go, Dog, Go! with very little help. Jamie: You know the word for water?! Sofi: There's water in the picture! That's what gave me the clue.