I have a bunch of friends who went to hanna sacks, and I have been in the school building myself. The girls are very nice, however, my friends all had issues with the administration that, if I would have gone there, I would have ended up switching to Ida crown (the modern co-ed school) because I was not a hashkafic fit for bais yaakov high school at the time. The girls are only allowed to wear, clear, french manicure, or pale pink nail polish to school, or no nail polish. Otherwise, they make you take it off. There are ten different uniform shirts, grey skirts, navy, and ugly plaid skirt (they phased out green skirts and replaced with grey), you could probably come up with a different outfit every day for a month if you get every single item from the uniform store. You are allowed to have internet in your house, you have to turn in your cell phone to the office at the beginning of every school day, their erev shira is mandatory, or your substandard (I know someone who dropped out, and the school tried to prevent her from being successful in school, she had learning differences to, so it wasn’t even easy for her to go to school all day to begin with). The school day is from 8:15-5:22 pm. Most of the teachers are very nice, but sometimes, my friends have told me that the administration almost made it not worth going to school there- or at least that is how they felt at times. On the plus side, on Rosh Chodesh, you can wear whatever you want, as long as it isn’t denim and does not have words on it.
Bais Yaakov high school, starts their school day at 8:30 and ends at 4:30. Girls are not allowed to have internet in their homes, I have heard from my friends there that the administration there is on the opposite extreme and doesn’t always notice, or attempt to deal with issues girls have. They have significantly fewer options for uniforms. On Rosh Chodesh, you are allowed to wear any white shirt you want, there are restrictions on colors you can wear outside of school, and some other rules.
Basically, there are plusses and minuses to each school, you really need to check them out before making the decision to move there, or you might want to consider sending your children to schools outside of chicago for high school. In terms of issues with administrations as mentioned above, they aren’t biased at either school about which girls are affected by their “unofficial issue treatment policy” I feel that you really need to know who is teaching the classes more than the hanhala. But thats just my take on it.