Tutoring an able child

It really depends on whether she is a child who likes/wants/needs to be stretched. If she is and you don't tutor you can run into problems of de-motivation, coasting, not really developing the resilience you need to get further in subjects, especially at A level. If she is happy where she is, then I wouldn't interfere.

You really need to be led by the child.

A possible downside might be if she starts to feel she's under pressure to get 9s across the board.

The problem with coasting is that she might benefit from learning how to apply herself to something she finds difficult.
The middle of the road ‘plodders’ don’t expect everything to be easy and are used to working for their results.
I don’t think it would hurt your academic able child to learn some useful study skills for confidence in the things that don’t come easily.

Schools are often reluctant to forecast 9s, so "on course for grade 8" may actually mean "on course for at least grade 8".

No.

I wouldn't tutor regularly, but I would look for holiday activities - eg coding/logic/maths, that will seem like fun, not deliberate enrichment.

It might depend on why she's not currently achieving her potential (if that is indeed the case). At yr 8 it might be not properly understanding a few things (my dd got temporary stuck because her teacher managed to totally confuse her about basic trig, rectified by me in about 10 minutes on the back of a napkin). Or it might be that she's a bit slapdash and prone to silly errors - that can affect good mathematicians doing 'easy' stuff, not sure if tutoring would help with that.

At this stage I suppose it might make a difference to which maths set she's in for GCSEs and whether she's able to do gcse FM if it's available at her school.

My dd is a tutor. She tutors a few very able children and one quite exceptional one. She thinks that most of them seem to really benefit from it, though she thinks the mother of the exceptional one is far too pushy!

For some, it's about making the most of their natural abilities. For others, it's more about building confidence.

I wouldn't say it's usual, but if she wants to go on to do maths at A level leading to a degree subject at a university that requires an A* then it may be a good idea as prep. My DS missed out on his first choice university as he only got an A. Depends whether she would enjoy it or not.

You’ve asked the key question - what is to gain from increasing a grade 8 to a 9?

Not much, I’d say. Far better to coast a little than push a child into burnout.

Besides, they’re only in year 8. There’s plenty of time for the school to to ramp up homework expectations, surely? In year 8 I’d be glad to see the school keeping it manageable.

I did for ds1, who was doing very well anyway, but I felt like he could do with some support to keep on track.

Tutor was lovely but a bit bemused (he'll get an 8 anyway... but it's your money type of comments)

We did 6 months, I think it helped set the idea that you can always improve and work harder, which has carried ds1 through into adulthood.