I too had exactly the same concerns last year.
DD (sensitive and not a fan of change) started in September and is absolutely loving it, her words not mine.
DD has a buddy who is in yr8, she wrote to her in June, they met at the induction day in July and they still keep in contact, even now!!
At the parents meeting in late September we met DDs form tutor, head of year, assistant head and the Deputy Head - all seemed to know DD - not sure if this is a good or bad sign though!!
They are split into form groups, tech groups and houses so plenty of mixing with a variety of girls not only in their year group but across the school as well.
Already had induction at S.Cerney water park, school disco, parents meeting, chamber concert evening & house drama is this week so plenty of activities. Most clubs are during lunch break (drama, choir, debating etc) and some after school (netball etc).
I know that I have made the right decision and have no concerns, the level of work and homework is appropriate.
They have fun and despite leaving for the bus at 7.25 and not being home til 4.30 DD is extremely happy.
Make an appointment to look at the schools you are interested in as now you have the results you may view them differently! Also ask your DD, she may already have a view but may not want to say!