Franklin had been expected to sing at the service Saturday in Newark, N.J. She tells The Associated Press she has been having foot and leg problems. She gave a concert Friday and says her legs locked up late into the night.
She says she sends best wishes to Houston's relatives. Franklin is close with the family. Houston lovingly called her "Aunt Ree."
Houston, who was 48, died Feb. 11 in California, the day before the Grammy awards. About 1,500 guests are expected to attend the private service.
