Answer: Sheila believe she will not loss weight because all her relatives are overweight, this means that Sheila has a "LOW SELF ESTEEM".
Explanation: Self esteem is the way an individual assumes him/herself to be, and the way their evaluate their own worth. Self esteem helps one to build courage about one's self. But when one has a low self esteem, their tend to loss hope on so many things. Such people will always want to give a reason for failure, and their will always give a Negative self talk.
Because Shelia has a low self esteem, she will not be motivated to push more further to loss weight, instead she will look for excuses to give a Negative self talk to her self.