a) If I may point this out.....please follow the correct net-etiquette in the forum and post your Q as a new thread or only in ONE of the past threads.
That said..
b) You are free to apply for F1 now since your DS-230 sent to KCC has no legal binding until you pay fees, face the DV-GC interview and sign it. (ie. you have not yet shown immigrant intent, technically)
c) But then, even if you get an F1 now, it will be canceled BEFORE your GC interview at the consulate.
So there is no point in worrying about the F1 at this moment. If you get F1 and leave for US before your Mom's interview, you will even jeopardize her chances too, unless you change your case to a 'Follow-to-join' procedure before her interview. (Talk to a good lawyer in USA if you want to do that, basically it is very complicated with the little time you have before Sept. 30th and may well be an unrealistic option)
d) You are in a catch 22 situation. Read these forums' wealth of info and understand your Mom's case well and make sure it has a 'realistic' chance of success at the DV-GC interview at the consulate. 'Cos if it fails you will have a hard time later to apply for an F1 visa since you have shown immigrant intent by then.
My best advise is, study your Mom's chances closely....if confident go for it (you only got all the info, we are just assuming its good and pray for your success! ). If not forget about it and go with your F1.
If you wait for GC interview, you will most probably get a decision by mid Sept. the latest. Ask time from your univ. But if you have to pay them well in advance, I would ask them to deffer the enrollment till next spring.
Wish you Good Luck !