It probably won’t have that much of a benefit for admissions to an “elite” college, when compared to any other summer activity.
HOWEVER. My kid did a summer internship at a well known neuroscience lab in the summer between her Junior and Senior years. It did not have any effect on her undergraduate admissions. However, it ultimately had a large positive impact on her ability to get an offer to her PhD program with her present PhD advisor, who was her #1 choice when applying to grad schools.
So, if this is what she wants to do wither her life, this internship will help her achieve her career goals, regardless of where she does her undergraduate degree.
If your daughter wants a career in medicine or research, it is important to remember that her goals are a career in research or medicine, NOT admissions to an “elite” college, or even a degree from an “elite” college.