Late to the party here but I'm currently serving. Enlisted in 2000, did a commissioning program at A&M from fall 2005 to spring 2008 and will be looking to retire from the Marines in 2021 or 2023.
The Marine Corps is 7% female. That is mostly concentrated in support roles. If she desires a combat arms (infantry, artillery, etc.), the Corps is making a concerted effort to integrate those fields but we are behind the other services in doing so--being blunt, it that is a role with a lot of upside potential but an incredible amount of negative potential and as a father, I wouldn't support my daughter pursuing that. If she is pursing a support role, I'd be open to it. Specifically, I'd look at jobs that have tangible skills after service. To me, those include legal services (para-legal), logistics and supply chain management, military police if she's interested in law enforcement / criminal justice, etc. Those fields also tend to have more female leaders that could afford her positive role models and generally people who can be mentors.
Generally, the Corps has the stigma of being the most challenging for females to succeed. I don't believe that is accurate. Standards are standards and the Corps is devoted to having the highest standards to be "the most ready when the Nation is the least ready." The bravado an dedication to service is what you have to believe in if you want to wear the Eagle Globe and Anchor.
I enlisted because my family was broke, mom had medical bills, and the recruiter promised me a $50k college fund if I scored high enough on the ASVAB. Looking back, I've got a bachelors from A&M, a MA from OU, and MBA from Liberty University, and I've been to 42 countries. My life would have never turned out this way without that decision to enlist and maximize the educational benefits afforded. Opportunities are there for someone who is willing to work hard and be devoted to achieving their goals.
Shoot me a message if you'd like to chat. I'm willing to share my insights to someone considering the service. With that said, I believe the other services would offer more tangible skill sets to someone looking to gain experience and pursue a degree. They also do a better job of locking you into a career field during the enlistment process than the Marines do. I'm not knocking the Corps. I've had a blast and the time is just coming for me to settle down--but when it comes to someone looking to make that move, I will be unbiased in my assistance and help make the right choice for your daughter's circumstances.