To do well in chem and physics you need much more than you describe here. You need a strong understanding of basic algebraic equations (what variables mean, how they get used, how to solve for variables when given multiple equations). You need to understand exponents and logarithms. Critically, you need to understand data tables and graphs. You need to understand y = mx + b as it relates to linear equations and the basics of what non-linear graphs look like and mean and how you can interpret them. You also need to have a good facility with arithmetic. Yes, most of the time in class you can use a calculator but you can't on the MCAT when speed matters.
If you went to good schools as a kid it's easy to underestimate these topics and assume every high school grad has a good grasp of algebra. This just isn't true. The math I used in the prereqs I mostly learned by 8th grade, because I was fortunate enough to be in accelerated math classes and grow up in an area with excellent schools. But in my post-bacc prereq classes I saw otherwise well-educated people struggle over and over and over in physics and chem. They couldn't even really get to understanding the chem and physics concepts because the minute equations went up on the board they were lost. They couldn't calculate a slope if given two data points. They couldn't solve for accelaration when given Force and mass because they just didn't understand what F = ma means in a mathetmatic sense. Many of them failed out of the classes.
The OP is doing exactly the right thing by preparing ahead of time and making sure that rusty math skills won't hold her back.
