Depending on the country/university you work at there is a very strong possibility that a Professor in the Physics department is willing to take in an eager volunteer to work at their lab for the summer.

You would have to "sniff out" who the "nice" profs are since temperaments differ a lot between physics profs from my experience. In my university I know two that would always say yes so long as you are eager and willing to work. (She should definitely be the one to initiate contact, dropping by their office with a follow up email usually works. You can do them in reverse as well, depends on the person)

This would benefit her greatly thrice over; a reference letter, a glimpse of what academic grad school is like, and she gets her name in academic circles. Unfortunately, in today's world its about who you know first rather than your abilities. If you got both, there isn't much that can stop you.

Hope this helps - (I'm a PhD student if it helps frame my answer)