I use something similar called nuro developmental therapy
its been very helpful in moving my dd forward (adopted from India age 23 mos.) But stuck in 3rd grade material ever since 8 years old.
I was reading an article somewhere on how a foreign adopted child can loose up huge amounts of word meanings when they switch languages. And it sounds like its a dialect of english which could be considered a language in its own right. I also a have one adopted at (age 5 11 months) she ran in the room the other day and yelled "The dogs broke the thing, the water thing chasing chatterer." Which I made her say properly when I discovered the Dogs broke the fountain base while chasing a baby squirrel. She also has problems with tenses b/c Chinese verbs don't conjugate.
Our therapist recommended this book
www.vocabularycartoons.com
have you also read Karyn purvises book The Connected Child? it has piles of resources in the back for helping the little ones and even older ones move forward.
My dd is also stuck in 3rd grade she missed out on the crawling stage (we are re inputing that into her brain). She is very much like your dd it was like I was reading about my child when I was reading your post. But i have seen much hope shes sitting next to me doing word problems... and shes 3 for 4 so far which is huge progress for us...
