It is difficult to determine if you are a good candidate for a Brazilian buttock lift based on height and weight alone, however, I would imagine you would be at 5'1" and 145. A board certified plastic surgeon can give you more information with a physical exam. The distribution of your body fat is more important than your body weight. If you are very muscular for example, you may not have enough fat for this procedure.
Web reference: http://www.williambrunomd.com