nope, you need to control your diet instead.

This I'm not sure. Maybe some other sifus can help clarify.

i try before. you won't get the whole stomach flab away. but the upper 2 pack maybe will slightly visible.
but need to control diet, especially dinner.
also take less sugar and carbs.

about 1 month, but it depends individual.
i'm weight 56kg. i feel sore for my lower back but not pain.

If by ab seperation referring to the lines between your abs, it will happen if your bodyfat % is low enough.
Women generally have higher bodyfat than men, so anything below 20% total bodyfat will take some work.

Your abs are always there.
What is blocking them is a thick layer of fat, this correlates with your total bodyfat %. Reduce this layer of fat, your abs will start becoming visible.