Children having had the SDR

My daughter is 3 years old and has got CP. We've recently been informed that she can have the SDR operation and having done some research on this and met the surgeon we want her to have this. However, Alyssa is due to start school next year and we are trying to decide when the best time would be for her to have the operation as there is intense physio afterwards and would she be able to comprehend why she will have to have this intense physio compared to a child that is 5 or 6? She is only 3 and a very strong willed little girl but would it maybe advisable to wait another year or two or would it be best to do it sooner rather than later so she can benefit from it before she starts school?
I'm looking for parents/carers whose children had the SDR and what your experience was with this and how it has affected them with school.
Thank you