With respect to federal income taxes, an inheritance is not taxable (with the exception of retirement accounts).
The estate would be required to file an income tax return (Form 1041) if it receives $600 or more in gross income. Since the sale of the house would certainly exceed that amount, you will have to file a 1041 to report the transaction (sale of the house).
However, there would likely be little or no gain (and, possibly, even a loss after selling expenses) on the sale if it occurred shortly after the death of your mother. In that event, there would be virtually nothing to pass through to you or the other beneficiary on a K-1 (the distribution of corpus (principal) does not have to be reported).
