This is one of my favorite subjects to comment on first remember all kids are different and second kids dont automaticly learn things. It is advise I give to everyone if your child will let you work with her at home on little things never force her but do fun things.
Like I teach mine left from right by pushing the grocery cart in the store and letting them tell me what direction to go. Or when they are little picking something up and saying red ball and everytime they pick it up say red ball. I started with all my kids as young as 1 like im teaching my 18 month old right now body parts pointing to my nose and saying nose now she points to her nose when i say nose.
My 4 year old is in preschool right now to and he can just barely write his name but he knows his phone number and how to spell his name. That starts as a game I say I know how to spell your name and i spell it then i say can you do it? Over a couple days I say I cant remember how to spell your name can you tell me and after a couple days he could. Same with the phone number my oldest three knew their phone number by 4 and to spell thier name but there was other stuff they couldnt do.
Now my 7 year old is in 2nd grade and in a 3rd grade level but my 12 year old struggles a little bit but is an excellent speller not an A student by far but shes juggling cheerleading to. She is young and bieng one of the youngest in the class would make you feel as though shes behind but she may not be at all. She may just be learning at her own rate and all kids do some kids pick things up quick like my 7 year old and others just dont like my 12 year old.
The important thing to remember is you are doing things the right way by helping her at home that is the best thing you can do. And overlook the things she isnt doing in school and improve the things she is doing and everything will come with time. Repeating things seems to work for mine but not work for all some kids just wont sit still like my son I have to make things a game so he will listen.
I guess I get it from my dad I was reading by the time I was 4 only because my dad taught me on a vacation reading road signs dont ask me how but they did. But I never got good grades at all and graduated with a C average all I could do was read well. My 7 year old will read everthing she gets her hands on chapter books and all but my oldest hates to read which is part of her school problem. I wouldnt worry to much unless she isnt progressing at all then worry but if she is learning stuff ok then shes a normal kid.