San Diego’s weather is now back to normal, and she would not likely need AC until late spring–not counting a couple of days of Santa Ana spells which she can live through. So reconsider moving out and sacrificing all the money already paid, especially since she is paid up for October. Meantime, take this thing to an attorney! If you can prove misrepresentation about AC from the beginning, the LL is the one who should be worried here. A good attorney will scare the bejesus out of this amature, and then likely negotiate a compromise and revised rental agreement.