My parents passed away left a house in florida there four children liv

Hi my parents passed away and left a house theres no mortgage its paid in full i have 3 siblings.my younger sister had my brother and other sister sign a notarized letter stating that my younger sister can have there share of the house.she wants me to do the same i said i would if she gives me my share of the property but she says for me to sign first if i choose to wait it out will it go through the courts and can the house just be sold and allfour of us get our share