You should move this to the primary education forum. In short, PH is higher rated academically and does 11+ prep, whereas Queensgate is probably more nurturing, less pushy/competitive. I am not a parents but know kids and parents at both schools.
If your daughter goes to Pembridge Hall, please share her experience as a pupil and your experience as a parent. My daughter has a place and I am confused about sending her there or QueensGate. So, an insider view would be much appreciated. Thanks.