You should always work to keep your technical skills up-to-date. But, perhaps more importantly for your internship, are the observation, communication and personal skills that compliment your technical skills and allow you to show people what you know.
Take the time to understand what the people you are working with do and what they know. The older person with a GED who has been running "the line" for 20 years often knows more about the nuances of the process than the overseeing engineer. Make yourself approachable to those folks.
Work on making your e-mails, presentations, and reports clear and concise and at the right level for the intended audience. I still struggle with this sometimes. Remember that managers often just need the facts and conclusions (and don't have the time to get bogged down) while other engineers may want all the details. Communication is often where girl engineers stand-out. So, I recommend refining and working these skills.
Finally, work on your network. Use the internship as an opportunity to grow your network for the future.
All the Best,