If you sold it for $140,000 a few months after she died, it would be worth about $140,000, not $90,000-$100,000.
Most likely dickcaro is correct and it will get a 'step up' in value, which means most likely there will be little or no tax due.
However, that wording in the trust MIGHT be a bad thing. It MIGHT mean that the trust will pay any taxes, which would be quite a bit higher than if the individuals pay that tax. But again, until the trust is thoroughly read, it is impossible to know what it going to happen.
