How did Rebekah end up bearing the curse she called down on herself in Genesis 27?
Rebekah bore the curse by never seeing Jacob again. After he fled Esau's anger, she died before he returned, ending her association with her favorite son. That permanent separation was the curse she called down on herself in Genesis 27.
Les explains that although Scripture does not detail other hardships Rebekah may have suffered, the curse she accepted was the permanent loss of Jacob. When Jacob fled for his life because of Esau's anger, Rebekah never saw him again. That ended her association with her favorite son, and Les thinks it was enough to break her heart. Isaac lived on, and Jacob later spent years with his father after returning, but Rebekah died in the meantime and never saw Jacob again. Thus she bore the curse through that lifelong separation.
And his mother said unto him, Upon me be thy curse, my son: only obey my voice, and go fetch me them.