Moms half

[idcw]

My dad (step) and my mom were married for 44 years when she died. They have 5 acres in Idaho. My mom told dad she wanted me to have the property when he passed away. Dad is now selling it. He told me that an attorny told him that he couldn't leagly sell it unless us kids signed off of the property. I guess, from what he said, that mom had half of the property (because they were married she had half of everything) so us kids were intitled to equle parts of her half. Is this correct? Can we stop the sell of the place? If the place sells are we intitled to equel parts of her half?