Independents close to or easy access from Oval underground station/SW9

If you are using the Northern line I would have thought that the Hampstead/Highgate schools would also be fairly accessible.

To add one more point is how reliable the public transport is and if there is alternative way to commute if the main transport is down, e.g. the frequent strike and cancellations of some of the trains service, can you do bus or other way to the school? Check the service reliability ranking of different London underground and overground line too

All the suggestions I have have already been mentioned, but I would reiterate what's been said about considering commuting time by whatever means make most sense (bus/train/tube) rather than distance. Distance is an irrelevance in London!

We also live very close but in Y6 so slightly ahead and a boy so looking at different options, though mostly co-ed.

I'd agree with what others who've said that the key thing is looking at the journey by public transport and how easy that is, rather than just actual distance. Driving to secondary school in London is not the norm. I also grew up in S London and went to one of the Dulwich schools, and barely anyone was driven then either. Lots got the coaches laid on by the schools, or public transport and even some cycling.

From the Oval the Dulwich schools are pretty straight forward. The 185 bus goes from right by Oval station and it's a short walk at the other end to Alleyn's and JAGS. It's not particularly quick but it's a straight forward journey. When we went to an open afternoon a few weeks ago quite a few Alleyn's children were getting it at the same time. It's also not too far to cycle, which our son would probably do.

We're also looking at Emanuel which as others have said is very easy from Vauxhall. I'm surprised to hear that your son-in-law has heard negative things about it. Everything I have heard is positive. We visited recently and liked it, though not as much as some of the others.

Our other option is St Dunstan's in Catford. There is a direct train from Elephant and Castle which works for us. It also maybe worth looking at some of the Hammersmith schools. We looked at Latymer Upper and the journey by tube is not too bad. It is a a bit longer but there is just one change and the walk at the other end is quite short. I think it is similar for Godolphin and Latymer. We ultimately decided that the journey was a bit much for us and we didn't like it enough. However, it's worth going to look at those schools and then weigh up the pros and cons.

I also saw that your daughter and son-in-law are thinking of boarding. It may be that leavers from their current school board but there really is no need for them to think that is necessary. I would say that going on to board is now pretty unusual for London based families. There's no practical need as there are so many schools in London and it really is easy to travel around.

@CurlsnSunshinetime4tea agree that important to 'experience the journey', including which areas the DC will need to walk through. Maybe something that the parents can explore before applying, ideally at similar times to school starting and finishing times. Quite a few of the schools mentioned are very close to the station (e.g. WHS, KGS,... ) and others in quite residential areas (e.g. PHS) which would make things easier on that front.
Personally, I would favour a journey with no changes, especially if changes are in a very busy station, but I can see lots of kids doing it every day.
Also worth considering that they are not 11 forever - it seems obvious but sometimes it can be useful to remember that. Although at the beginning it can be attractive to drive them (and we know some parents that do that in Y7) the DC are keen to get their independence - so a school with good public transport links and, ideally, in an area where they can meet with friends after school.

I know some girls do train from Vauxhall via Clapham Junction to Kensington Olympia for SPGS, so maybe worth considering the West London schools?

Putney high would also be easy from Vauxhall

For mid-high level selective schools and 20-30 mins commute from Oval via public transport:

CLSG
JAGS
Alleyn
FHSS

I would say traffic is much worse towards South West London direction so North the river or East is better bet.

I think it’s a mistake to rule out Emanuel based on what may be outdated second-hand views. Ten years ago it was more of a backup school, but it has made great strides under the current Head. We liked it very much when we visited, and their comms about admissions are first-rate.

Portland Place if they’re considering Queen’s College? It’s essentially the same commute.

More House in Knightsbridge?

Newton Prep in Battersea goes to Y8. So does Hill House in Chelsea.

@CurlsnSunshinetime4tea The commute is indeed an important consideration - 30-45 minutes door-to-door is pretty standard in London and quite a few kids do more. In addition to the length, worth considering the complexity of it (are changes required, etc) - if your DGD can get to Vauxhall train station, that would open up the option of quite a few schools not only in Clapham but also Wimbledon and Kingston with direct train links.
Worth noting that some of the schools have sports fields in different locations and the travelling to them might be required at weekends / out of school hours and the transport links might be more of a challenge.
Quite a lot to factor in, but it seems that you are very much on the case.

This is a great list. To add, in case helpful.

• Thames Christian school, mildly selective but with strong SEN provision
• Streatham and Clapham High Street (mentioned by the PP), has had a recent change in leadership but GDST membership gives it structure / level of certainty, parents seem mostly happy with it (we know quite a few girls happy there), less selective than other GDST but good results
• Wimbledon High School (easy train ride from Vauxhall), highly selective but definitely not a hot house, junior school with some 60 places for girls at 11+
• The Hall School (Wimbledon, as above, train ride from Vauxhall), probably easiest entry of the ones mentioned. Seems to be on the up with a charismatic head teacher.
• Kingston Grammar School (train from Vauxhall to Kingston), co-ed, a bit less selective than WHS (but on a par or a bit more than Emanuel, I would say - co-eds in South London are very popular and in demand

As others have said, visiting and getting a feeling for the school and the community (parents, children) is really important and is speaking with parents with direct experience of those schools.

Emanuel school in Clapham but quite competitive to get in now. Though great for all rounders type and those into music, drama, sports. Head been there 7 years, so check no older comments due to changes.
JAGs, super selective so will need to get the grades.
FH, new head this term so the fabulous head have left. Therefore, have to see the direction the school will go. There will be changes so need.
Queen College.
City of London girls, super selective.
Queen Gate, smaller school and no uniform.
Alleyn, junior school so fewer places at 11+.

All schools have open days, so parents should sign up and go with DC if possible. The Open days and the 11+ process with different exams styles can show and change schools preferences.
London 11+ consortium is 1 exam for a bunch of girls schools, therefore you don’t want to put it all in 1 basket in case of off day, cough or cold etc. Therefore select a few different exams on different days.
Also, get a feel how many pupils travel and how far? Time starts in morning for clubs or sports and clubs after schools.

Yes, the very monied aspect of FH is my only criticism of it. The school mitigates it, school trip etc. aren’t ridiculous, the uniform is strictly upheld and no more expensive than some state schools. But if the girls are wearing Moncler at the weekend and VI form and instafamous as parents you have to hold strong boundaries.
My dc went to 10 schools large family and we started state, moved overseas and came back for secondary. The teaching and pastoral care at FH was the best we found anywhere.

Jumping on this as I'm in a similar location and also on the lookout for secondaries.

Any of the very central ones like City would be straightforward to get to.

I'm looking more at state schools but maybe open to private too.

Any school where you have to 'keep up' to fit in sounds hideous. My DS goes to one of the 50k/pa boarding schools and there is no sense of that whatsoever.

Usually the Prep Head has recommendations for schools dependent on child's academic level and personality.
Also- many families in the Kennington Park/Oval area with strong online (and in-person) parental networks- your daughter could reach out to local parents and ask where their children are going and what the commute is like.

London Park is worth considering
Is the child at a private prep? What is their advice?
Do they want coed or girls only

FH really is a great school and how she fits in will depend on your dd and sil. They’ll need to “keep up” but not spoil your grand daughter remembers the £800 coat we bought dd over 10 years ago
It’s a better school than the Dulwich ones imo, but that’s a big caveat.