LEH or Tiffin girls

DD school has a handful of girls from LEH juniors. I've met some of the parents who did say they would equally have been happy to keep them there.
Somehow I did also hear on multiple occasions, about how great Hampton is, often comparing it to LEH. There are many siblings attending both schools so parents talk about the two schools together. Maybe LEH being a girls' school kind of adds to the intensity that makes the experience not as great? Not sure.

We previously had a similar dilemma with a different independent school, which we have chosen and not looked back.
My child enjoys a highly academic peer group but also benefits from a really rounded education. Music and sports are top notch, and there are so many things happening during the school day. Lots of enrichment happening every week as a form group, girls do a variety of sports (including swimming) during PE and in clubs with lots of opportunities for fixtures, termly music ensembles and solo concerts to show off what they practiced, actually doing something fun and relevant in food tech and DT. We are working parents and I wouldn't be able to outsource the rounded experience elsewhere, because I wouldn't even know what kind of things I could offer her. It is greatly nuanced and imbedded in their day to day. For this reason, I probably can't comment on what a Tiffin girls' day to day looks like.
It's easy to converse with the school with any concerns I have, small or big. I've been getting quite detailed feedback about my DD's progress and noticed the specialist tutors understand my child well.

Tiffin girls will have a great peer group and an invested parent body but that's pretty much it, it cannot provide much more than any other state school. The school does seem to be run in an outstanding manner and will have less distractions supporting disruptions in class. I do know parents of girls who are very happy they don't have to pay anything for such a great school. One thing I heard is that it is pretty strict, you get detentions for things that you probably wouldn't in a private setting (e.g. forgetting your lanyard).

I don't have direct experience of LEH but have heard positive feedback from friends. Do check on your gut feel and try to speak to some actual parents. I have not been to LEH for the open day but I heard girls are pretty competitive there too. I actually got the opposite impression of girls from Tiffin, perhaps because of the way the open day was run (it wasn't a two girls in pair showing around a small group, it was open classroom and standing around at posts to answer questions), that girls seemed more reserved. It's not easy to tell by observing a small group of girls.

Do you have other children?

I live only 100 metres from LEH and know several employees there who chose not to send their own children or grandchildren to the school even with the discount they receive. They said all that it is not worth it. Furthermore, a neighbour of mine had one daughter at LEH and sent her younger daughter to Kingston Grammar instead. The sentiment regarding Hampton School for Boys is quite the opposite, however, as the staff there seem very positive about the school environment.
I also know three mothers whose children attended or are currently attending Tiffin Girls' School. While it is true that state schools are often underfunded, the management at Tiffin Girls is excellent, especially considering their limited resources.
That said, I personally would never choose a single-sex school for my child. I realise that is just my opinion and that others may have different perspectives and I fully appreciate it.

I live locally and am very familiar with all the schools in SW London via my dc and work. I can assure you the competitiveness will be at both schools but it’s coming from the parents and dd not the teachers at the schools - it’s in all the top private and grammar schools in the area. Your dd is obviously bright, where does she want to go? She will probably enjoy both and get the most of out of both so you need to take your gut reaction into account.

Tiffin girls is 1 of the top state schools in the U.K. and is in the top 50 feeders to Oxbridge globally. LEH is an excellent private school with a large cohort from the junior school feeding through and a percentage who leave after year 11 to go to more academic private sixth forms. Each year several of LEH juniors go to tiffin instead of LEH seniors. Have you read the Ofsted report on the Tiffin website that was published last week? Your dd will do well at both schools, it comes down to the cost etc.

Save the money and give it to her as a deposit on a property. Send her to Tiffins

Tiffin Girls. Absolutely. LEH does not compare

It’s really up to whether you want to spend £250k over 7 years or not. She will almost certainly end up at the same uni via either school. Tiffin is harder to get into than LEH so she has done very well (and is not on the WL) so she will be fine academically and should not feel intimidated.
2 things you can think about are how to feel about losing the LEH deposit if you go for Tiffin and how to feel about giving up your Tiffin place and how happy that would make another family? Also uni is really expensive if you want to spend the money then instead and save on student loans etc.