You can check with below websites, there are lots of nursey school information details for your immediate checking. You can contact the one near at your working places to see if there are seats available in March. You may also visit another discussion area (談幼兒院) for more advices.
In Mongkok,香 港 基 督 教 服 務 處 雋 匯 幼 兒 園 has extremely good reputation, and so it is very very popular and has got a long waiting list. 保 護 兒 童 會& 救 世 軍 are also good and thus very popular. They may not have vacancy to accept 插班 if you want to send your girl to N1 in March. I agree with COMET's suggestion that you should check with the nursuries one by one la...
My mom looks after my daughter for me. But the location of 雋匯幼兒園 is not so convenient to her so I did not apply.
It's good that you've made a decision. May I remind you that to play safe, try to apply for more nursuries in Mongkok if you really want your daughter to study in Mongkok area next year. 雋匯 always have a long waiting list.