Jesus Christ!- she is 6 in year 1? I despair of the primary curriculum that labels such young children as failures. A tutor at the age of 6? Seriously?
They should still be playing at this age, running around outside, being silly, not being forced to learn things they might not be ready for.
In many parts of Europe they don't start any formal learning till 7 and withing three months outstrip our poor tinies who have been chained to desks since they were 5, it just breaks my heart.
Fucking Michael Gove 
Emerging in year 1 work is where they should be at the end of the first term. We are only halfway through term 2 so really not that far behind.
DD1 was one of the top readers in her year when she was in year 1. By the time her class got to the end of year 3 they were all at much the same level. She really struggled with maths and was in the bottom set of 4 in Junior school. Was just about average when she went to secondary school.
She eventually passed A level maths with an A grade...
DD2 took much much longer to get reading. I would say it was year 4 before it really clicked. Two years later she passed the 11+ and got a place at grammar school.
Newsflash:
CHILDREN DO NOT MAKE LINEAR PROGRESS
They are not little automatons who will remember everything they are taught. Some get it straight away and others take longer.
As others have said- foster a love of learning and reading through stories and play.
I don't think she realises she's not doing as well as the others or anything, when I got home last night from PE she proudly said " I know you're proud of me as I always try my best " she is great at dance and drama and does those clubs and enjoys them
She sounds just lovely! Encourage her love of performing- it has many benefits which develop skills for many other areas of learning.