I agree. I'd also try and look at staff retention - constant churn not great indicator.
We moved so kids ended up in a primary most tired to avoid - in year transfer and where places were - but it was actually very good - older two had small years and got pushed and a lot more attention. DD2 less so - partly a new teacher with less ambitions but also a full class by then but it was still perfectly fine experince for her.
Secondary - we chose one that had a steady climb.. Year before second child was to start and just before eldest had choses and started in Y9 some GCSE it went to shit. WOnce eldest had started GCSE we were stuck here as next child started when one finished.
They did well academically - I think girls would have done even better else where but it was more than enough to go elsewhere for A-levels - DS did brilliantly mostly due to us at home as his GCSE were a mess.
They all got fed up of constant class disruptions even in top sets and bullying was not dealt with at all - pastoral care which had been excelent when DD1 started was stripped out and completly gone by next child start. They were all very pleased to leave for sixth form. Older two at uni - but then DH and I are both graduates and it di feel we had to constantly fight low expecations school trhew at them.
However you appraoched the school - and not just us other parents - SLT were immediately hostile and defensive. It was pretty awful all round TBH - we were all glad to be done with them. Socially they all had friend groups - though at times they all had issues mostly before group changes.
I did speak to another parent her kids cousins were at best state school in area and they had so much just on tap D of E- orechestra spot events school would get coaches for - she was replicating as much as possible often through girl guides but it was a lot of work and money on them. C school groups would start and reapily peter out.
You can't move in year here - there are no places at other schools - cheaper housing mean families have moved here since we did and school places that were once there just aren't - there actually school building in area. So I'd look into that before assuming an in-year move will be possible.
If it's that school or nothing - keep a close eye on her education and step in as soon as it looks needed - don't wait. Make sure she gets ambitious messaging from home - it may be less an issue at the your school but be aware. Make sure she does stuff outside school - so if friendship groups go south she knows it's not her.
If it's a soild but not so great school with good behavior where bright ones get a lot of attention - could easily be very postive experince for her.