My mother's brother died. He was not married and had no children. He has a house and property. My mother has a sister. Is it possible for my mother to NOT inherit her half of the house and property but give it to her chilren?

Was there a will?

Louisiana has the most complicated laws of intestacy in the US.
If the decedent has no descendants, his separate property will be inherited by his brothers and sisters, or their children if any of them have predeceased the decedent, subject to a usufruct in favor of his parents. Half brothers and half sisters inherit according to their lines, thus they may inherit only a half share, and that half share may or may not be subject to a usufruct in favor of their parent. If there are brothers or sisters on only one side, they inherit to the exclusion of all others.
Consult an attorney.

The simple answer is no. She has to accept the property before she can pass it along to you.

There is no provision in the law for your mother to be "skipped over" unless she weren't alive.

Your mother may be able to pass on the inheritance in which case it goes to the next in line, which may not be her children. Or she can gift the inheritance to her children. Either way I would consult an estate attorney