Lincoln recently joined Sen. Jon Kyl (R-Ariz.) in trying to amend the Senate's small-business jobs bill with a measure creating a permanent fix for the tax.
Their proposal would tax estates worth more than $5 million at 35 percent. These amounts would be phased in over a 10-year period and be indexed for inflation.
The senators attempt to add their proposal to the small-business bill was rejected by Democratic leaders.
The estate tax is currently repealed but returns in January with a 55 percent tax on estates worth more than $1 million.
Absent congressional intervention, Lincoln warns farmers will be hit hard by the tax because their assets are tied up in the equipment and land they use to keep their businesses afloat.
"They're all people that have their money, their resources, their assets tied up in something that's not liquid," she said, adding, "You look at farm implement equipment; some of it is $400,000 or $600,000 for one piece of equipment. If you own 1,000 acres of property that's worth $2,000 or $3,000 an acre, you're going to have to sell your business to pay the tax."