If you father and his wife had separate trusts, the house was in your father's separate trust and that trust was a standard (typical) grantor trust, then the trust became irrevocable upon your father's passing, and the basis of the house would be its fair market value on that date.
If the house remained in that trust until it was sold, then the sales proceeds would be held in the trust until distributed and when distributed to the beneficiaries it would be typical for the trust to issue K-1s to the beneficiaries who would then assume the responsibility to pay any tax due (federal and state) on the gain; each beneficiary would receive a K-1 for their portion of the gain in that instance. If the trust had paid the tax for some reason, then the proceeds would be distributed to the beneficiaries essentially tax-free.
It is critical to read and understand the terms of the trust, however. For example, did the trust give the right to your father's wife to live in the house for life or as long as she pleased? Also, your facts are somewhat confusing in that you stated your father's wife "sold the property" but also that your "brother is the trustee". Typically, only the trustee would have the right to convey the property out of the trust. Again, the terms of the trust need to be examined. Regardless, under normal circumstances, you and your brothers would receive state and federal K-1s (the equivalent for Nebraska) from the trustee.
