no
Yes, go look them up.
Yes, Whitney's father, John Russell Houston Jr., did remarry and Whitney did have older step-brothers. Whitney Houston's mother, Cissy Houston, was married before she married Whitney's father. Cissy's first marriage produced a son, Gary, Whitney's older half-brother. Whitney's father was married once before he married Whitney's mother. Thus, he already had a son, John Russell Houston III, from that previous marriage. And after divorcing Whitney's mother (with whom he had her and a son Michael), John remarried and had a daughter, Alana, with his third wife, Peggy. Gary and John Houston III are her half-brothers. Alana is not John's biological daughter, he adopted her when he married Peggy.
No, Whitney Houston is not single.
She had one biological brother (Michael), two step-brothers (Gary, from her mother's first marriage; and John, from her father's first marriage); and one step-sister, Alana (from her father's next marriage).
Many pictures of the Houston family can now be done through a Google image search. The family televised Whitney's funeral, and pictures can be seen of the family. Please refer to the related link, for some images of the family.
no
no
no
No
No, Whitney Houston did not have any sisters. She only had two brothers, Gary Garland and Michael Houston.
Yes
yes
One
No because she had one brother. And his name is Michael Houston.
two brothers
They are her brothers, I believe