Help me find a movie

The main character is an adult woman.

At the beginning, she doesn't know that her memory has been erased, and she spends the entire story searching or doing something.

The ending takes place at a white glowing cube (resembling a protective capsule), which appears only at the end.

The heroine opens the cube's door, initially expecting to see someone, but there's no one inside. This triggers a memory, and she walks around the cube, opens the door on the other side, and finds a small child inside.

It turns out she erased her own memory and hid the child in the cube to protect it.