My wife is Swiss and not a USA citizen (although she is a USA tax resident because she is half a year each year in the USA) and I am a USA citizen.
My wife's mother(a Swiss citizen) just passed away and left my wife considerable money.

My question is whether my wife has to pay inheiritance taxes in the USA?

Thank you for your help,----------------------Samoosh

No, there is no inheritance tax in the U.S.
You may need to file Form 3520 Annual Return To Report Transactions With Foreign Trusts and Receipt of Certain Foreign Gifts if the amount exceeds $100,000.

Thanks MukatA,
This Form 3520---who files it, me or my wife? Until now I have been filing joint IRS returns with my wife but this year we are going separately.
My wife really has nothing to report and probably would not have filed a return. So,--must she(or me) file the Form 3520?
Also,---the estate will be settled in Switzerland. You state that my wife has no tax obligation. But when she brings some of her inheiritance to the USA, is she then liable for any IRS taxes on the inheiritance portion she brings to the USA?
Thank you very much. I know some of this may be repetitive but the whole subject is very complex for me and I would like to be doubly sure.
Thanks again, ---------Samoosh

Your wife got the money, so she files the Form 3520.

She will be liable for NO taxes on the inheritance to the IRS.