Quality of activities is more important than quantity.
While having some solid extra curriculars won't cover up a bad GPA, it can be a deciding factor on a more equal academic footing. Say the admissions board is looking at your daughter's application and the application of another student and comparing them. They are both roughly the same academically, but if your daughter has some good extra curriculars over the other student, it will give her an edge.
I would emphasize leadership ability in groups. If she was President (or secretary, treasurer, VP, whatever "office") of some club or other, mention that. Any group that she was a part of that had significant accomplishments (state champions, regional champions, whatever) is worth mentioning. Mentoring type groups are good to mention since many universities have a big thing about "giving back to the community." If she's been a regular member of the local basket weaving community for the last couple years... I'd probably leave something like that off since it doesn't really contribute anything other than she obviously has free time.
Unfortunately being middle class does hurt her. Many scholarships are classified as need-based. Being white, not necessarily a bad (or good) thing. Many scholarship providing groups, though labeled as "hispanic," "black," etc, are open to everyone. Even SWE (Society of Women Engineers) accepts men and offers scholarships.
Something I heard once was that it was an excellent idea to go visit your high school guidance counselors about scholarships. I was told that they have file cabinets full of scholarship opportunities. Many of them are small, local opportunities and nobody ever hears about them, so nobody applies. Even if you are completely unqualified for a scholarship... if you're the only applicant (or the best of a small bunch) they'll give it to you. Lots of little scholarships do add up.
Other possibilities to help defray tuition costs are getting a job on campus. Many professors advertise for undergraduate teaching/grading assistants for their classes. If your daughter takes a class, does exceptionally well in it (typically an A) and gets along with the professor, definitely talk to them about possible opportunities doing that in future semesters.
Good luck to her!
