One is a cancer cell that was part of the body of a dead organism.
The other is the entire body of a new living organism and member of our species - a human being. Glad to clear that up.
Objectively false. That cancer cell is not going to somehow grow into a new body for Mrs. Lacks. For one thing it has fucked up DNA, so even cloning, which has never been successful with humans anyway, is already out. And even if you were able to make a Lacks clone through scifi means that clone would not be the same organism.