@JLR Would you be willing to share how your daughter was accepted to university at such a young age?
We live in Australia, so our exact route probably won't help you much. But I can say that over the years universities and colleges appear to have improved their non-traditional entry pathways, so have a look around to see what is on offer at the institutions you would consider. I've also heard that homeschooled students are valued by higher education institutions because they are generally more self-directed learners than high school graduates.
For some details. Our daughter attended a mainstream school from kindergarten to year three, then year 5 before returning to homeschooling. She is now officially enrolled for homeschooling for year 10 with our education department, but her university subjects and a vocational course she is undertaking (Certificate lll in Dance) count for her elective subjects (our assessor from the education department is wonderful and flexible). I teach/assist her with maths, English, history, geography and science. She also dabbles in French, music, etc. for fun.
Our daughter started working towards university entry by completing a few online short courses at international universities through websites such as Future Learn. There are lots of sites out there offering similar things. Through Future Learn the courses are free, but it costs about $50 to get a certificate of completion for each short course. We paid for a few certificates in case they would help with a future college application. In the end I think only one was used on her application (a Preparing for University subject). Otherwise they were happy to give her a chance, probably largely because we would be paying upfront for her subjects to begin with.
The university she now attends has a pathway where you can pay upfront to complete individual subjects that will count towards a Bachelor degree. It is around $1700 per subject as she is completing a science degree, but the cost was $800 per subject for my Arts subjects when I did the same thing a few years ago. After a few subjects she can apply for a Commonwealth Supported Place in the Bachelor degree program. This will basically give her a loan to pay for her subject fees that is only indexed to inflation (no interest). This is the usual way an Australian student pays for university. You repay the loan slowly once your income exceeds about $50 000/year.
I know of other universities that offer other pathways, such as a 12 month on campus course for those who haven't completed mainstream schooling, or were unable to enter university through the usual way. I have a friend who undertook this course after homeschooling.