In response to the original poster, I would suggest that you may want to start studying at a Kumon centre at the end of her year in Reception. Perhaps at the start of the summer holidays of that year, just prior to her starting in Year 1. This will have enabled her to get used to a classroom environment and to be less tired to attend a centre after a day at school.
I am the owner of a Kumon centre and this is what I usually advise.
Attending a centre is preferable over working through the Kumon workbooks at home for all of the added benefits you get from attending a centre. Not only do we work on developing maths and English skills, but also the necessary pre-requisites to be a successful, independent learner over time. We take into account the need to develop concentration, stamina and focus. The need to develop correct pencil holding skills and also to be certain that we are giving the just right amount of work for your particular child. We observe children to see how they tackle the individual worksheets that have been set for them and this informs our decision on how we next progress. It is not all about worksheets, worksheets, worksheets, but about skills, skills, skills.
As a parent, you will need to consider your daily routine and ensure that there is a certain amount of time available to both of you so that the work is completed. Initially, you may spend 10 minutes a day on one subject. As students advance, and in particular, when they start to advance ahead of their age, the time requirement increases. Again, the Centre Instructor will tailor your child's workload to suit the time that you have available every day.
The maths programme initially focusses on developing strong mental maths skills, in terms of accuracy and fluency and there is no conflict with the National Curriculum. The current Government has acknowledged that the National Curriculum in its current form has failed and is failing many children, and standards in this country are poor compared to other countries around the world. They are now realising that children should be more fluent in the basics and are currently reviewing the curriculum to incorporate this, hopefully having less emphasis on a variety of written methods but learning fewer methods more thoroughly - just like Kumon. The ultimate aim of the Kumon maths programme is for children to work with high level maths with competence, confidence and ease. For this to happen, and we have thousands of students who have these accomplishments, children need to complete the foundation work of addition, subtraction and multiplication first and to a very high standard. This then leads to excellence in high school and beyond, and also has an effect on other school subjects as the student develops in to an independent learner with good self-study skills.
For Kumon to be successful, parents have to be committed to the daily routine of around 20 minutes a day for one subject, be encouraging and not "pushy" in their approach and communicate with their Centre Instructor regularly.
I am seeing an increase in the number of younger students enrolling at my Centre. These young minds don't see completing the worksheets as "work," they see it as "grown up." Doing what the "big" children are doing - it is all very aspirational for these young learners and they develop the learning habit and attitude at a young age that stays with them. "Work" is the term that the adults around them use and for some reason is perceived as a negative thing. Practising football skills day after day doesn't seem to attract the same negativity as practising their writing or number skills does.
I hope that at some point in the future, the original poster does decide to investigate Kumon further. There is some great work and great achievements being realised each and every day at the thousands of Kumon centres around the world with children of all abilities. You may find that it is the best thing you have ever done for your child, a sentence one of my customers uttered to me a few weeks ago.