Does your mother cooking supper now?这句话对吗？？？如不对应怎么改？？

不对的
后有now标志着现在进行时，应用be动词+动词ing形式
而does是助动词，后面不能用cooking
修改：Are your mother cooking supper now?

错,应该是Is your mather cooking supper now?从now可以确定是用现在进行时,所以用be动词,your mother是第三人称单数,所以用is

错！
are your mother cooking supper now?

Is your mather cooking supper now??

对。