There's this (wrong, based on my own experience reading anecdotal evidence) idea that because you are older, results won't be as good. I actually find older women often get significantly better breast growth than younger women, excluding those that take hormones during puberty and even then. There are so many factors at play, the amount prescribed, the concentrations of androgens in the body, sensitivity, metabolism, stress levels, eating habits, fat tissue, etc.
I say forget how old you are and expect the unexpected!