In order for her to sustain this goal and without depleting...

In order for her to sustain this goal and without depleting her principal, her investments must earn an average of 11.8 percent. If she would invade the principal for two years (until Social Security and the pension kick in), using $1,100 a month, the remainder of approximately $311,314 must earn an average of 10.5 percent, assuming $ 600 monthly from Social Security and pension.