I have never seen an "official" statement about how her mother died. However, it has been made VERY clear by the girls - including Tiffany herself - that her mom died when she was young.
The point is, the reporter is saying that her dead mother is supposed to be relocating to Korea. He also states that her contract is almost finished.
The reporter needs to grab his ear lobes and pull his head out of his a$$, as it is obvious he doesn't know what he is talking about.