Tracy Jennings, Works at Noodle and here to help!
Congratulations on your child's achievements and the options she has for her educational experience. My advice is to make your decision based on her objectives for middle school. Here are some things to consider in making your choice:
Does your daughter know what her favorite subjects are and have a sense of what major/career she'd like to pursue? If one school is known to have a really stellar science teacher, and she's set on becoming a biologist, that's a very important consideration. A mentor this early in her academic development would be a huge asset as the number of her academic choices expands. If she's undecided, then variety of coursework would be beneficial.
What type of environment suits your daughter? Would a larger group of peers excite or overwhelm her? Is diversity in background something you value? Pin Oak and Grady offer different learning environments. Pin Oak has more than twice the student population of Grady MS, and the demographic profiles are slightly different (as you can see on the Pin Oak and Grady Noodle profiles).
Is convenience to your home important? Does your daughter participate in lots of after-school activities unaffiliated with the school or is she looking to get involved at school? Pin Oak, as the larger school, has more extensive and varied options to get involved at school, which might interest your child. However, the ease of getting to and from school shouldn't be underrated if she has extensive demands outside the classroom (eg. travel soccer, babysitting work, health concerns).
Also, it's crucial is to involve your daughter in the decision-making process. What should be the most important factor in the decision-making process is the visit to the different schools. You might find she has a marked preference for one over the other. Middle school can be a difficult transition time, and it's important she feels like she can be her full self in these new surroundings.
I'm speaking partially from my own experience — I was choosing between a private parochial school, my zoned public middle school, and a magnet middle school program (and decided to attend the latter). Being able to enter sixth grade with a sense of ownership over my choice to attend this new school gave me a confidence that was crucial later in my later educational decisions.