schools in Johar town, Faisal town or gulberg for O Level

hiii, so, I'm looking for a school that offers O-levels in JT, Faisal town and Gulberg for my sister. we moved from FSD to LHR so I dont know much about schools here. I don't want her to go to an all girls campus and we can't afford a 40-50k per month fee. I planned on sending her to LGS since that's where I've studied from but now idk. she's starting her Olevels this year so any suggestions ??