Questions to ask yourself (and answer honestly):
1. Do you and your daughter have the kind of relationship that can withstand tutoring across the kitchen table? Try it and see. Some of us have children who respond well to a parent's tuition. Some of us don't. Some of us have one of each.
2. Do you have the time to give to it? Ideally you are looking at an hour or two a week throughout Year 5, to encompass VR, NVR, Maths and maybe English, depending on which schools you are going for. You will also be spending extra time planning your tuition, marking the work, deciding how to deal with weak points etc. It is time-consuming and easily overlooked with other family demands. You, the parent, need to be honest as to whether you can give it the commitment it needs.
Paying tutors is increasingly the norm, but families often supplement this with their own DIYing at home. I think many of these would have been perfectly fine dispensing with the tutor because they managed amazingly, but they needed the confidence of having the tutor there to back up what they were doing at home. Some kids will sit still for a tutor one hour a week when they are reluctant to do so for their parents.
It is perfectly possible to do it yourself, and there are indeed a lot of us on this site. It doesn't mean it's the only way to do it, but if you go the tutor route, make sure you ask questions about the types of questions they will cover and what they actually do in lessons and with how many other children. And don't fall into the trap of thinking that just because they have a tutor that you do not have to keep an eye on what they are being taught and will need to supplement at home.
There are a lot of myths about over the exams. There are a lot of people going to tutors. Yes, some exams are harder than others. Yes, the kids need some preparation. It is hardest the first time round because you don't know how high the bar is set and how your child will react. It isn't pleasant. But it is a necessary evil in Trafford if you want to access the grammar schools. Just don't fall into the trap of thinking that a naturally bright child will get in without being at least familiar with the exams and used to the tight timing.