Cut out pictures from magazines or print out pictures from the Web that represent jobs your child might want to do when she grows up. Together, brainstorm about what skills and talents these people must have in order to be successful. Hopefully reading, writing,
math, and some other solid educational building blocks show up on this list.
You might also go to the Bureau of Labor Statistics Career Information site and find out what skills it takes to be an architect or a veterinarian, or to work in any other field she's interested in. Help your child turn developing these skills into learning goals for the summer.
If you know or can find someone who actually does the job that your child picks, ask if that person would be willing to help increase your child's motivation. A shopkeeper, an athlete, or a stockbroker who is willing to check in with your child periodically about her progress with summer work makes the task more important and more real. Consider asking your own colleague, relative, or friend if he or she would be willing to be an "e-mentor" who would check in with your child via email over the summer.