Whitney Houston's sister-in-law, TINA BROWN, has stunned the pop star's fans by revealing rumours the singer is suffering from a brain tumour could be true. Brown, who exposed the depths of Houston's drugs hell in a National Enquirer interview last year (05), has gone public with the HOW WILL I KNOW singer's latest health crisis. The former model and drug addict admits she's puzzled why Houston's family hasn't come clean about the singer's new medical battle. Brown says, "The talk in my family is she does (have a tumour). (A family member) said the other day, 'It's getting worse. Let's take her to the hospital.' And (another family member) said no because of the media. "She's (Houston) going into her states and everything. All the symptoms are there. "They called from California stating that she had a tumour. Why are they keeping this a secret, I don't know."