that would be hard when i say reach the ages of 20-30 where she'll be asking me about marriage and so forth, and when i take of my headscarf. i know that she will most likely never reconsider her beliefs and nor would i force her to, it's an interesting and and emotionally powerful journey of truth that one should discover on their own, i believe. the thought of not speaking to her makes me sad, and you're right i should stop seeking acceptance, but its vital if i want to keep in contact with her.
You have 4 years to slowly get her to accept how you life your life. Don't go for the all-out approach, do it slowly. My advice to someone else was
1: Write down a list of things you do in the name of Islam (praying, fasting, etc)
2: Write them in a specific order, so that the one that would raise the fewest eyebrows if you stopped doing it is at the top.
3: Stop doing the item at the top of the list.
4: Wait for people to get over it, then stop the next thing on your list.
If you cannot outright stop, for example praying, then just pray less and less until eventually you don't pray or go to mosque. Make sure you fill your life with something demanding, such as a university education, that way you "simply don't have time" and won't be perceived as "just idle".
Not been through it myself, but small changes over time are typically easier to implement without resistance.