I am going to assume a lot of things but only you know if I am right or not.
First is because of the age, you both can speak well. Therefore you have a way of communicating already.
Second, she has not been really tested yet to find out if she can benefit from using hearing aids, otherwise you would have said so. If she has been tested and found to be "totally deaf" find another doctor!!! It can not never be assumed that a hearing person that has an "accident" would lose all thier hearing, such an accident would have to also kill that person. I am not saying she can or can not benefit but give it a new try with a different doctor for a second opinion.
Third, you both are going to have to learn to lipread. Notice I said both of you!!!! Yes, you can if you want to but she must learn to lipread. For you to really love her and want a relationship that grows, you will yourself become involved in learning along side her. Once you both learn to lipread you will find it a brand new world but also a special way for only the two of you to share.
Last, consider her family and friends. Up to this moment, she has never associated with deaf people nor the "other" ways deaf communicate. So now she will feel the need to find a place within the deaf communnity and try to understand deaf culture. Under no circumstance should she "lose" nor "neglect" her contact with family and friends. Yes, these same people are going to go through the "shock" of having to find a new way to communicate with her but, with serious effort, they will find it easy. In their mind it is "going to be hard, if not impossible" to communicate with her. But it will be their lost if they dont do their part.
I know the first thoughts of this long difficult road seems a burden to you and her but going down that road is not a choice, it is a necessisty now. Nevertheless, you both do not walk alone, there will be a crowd of people who will happily walk with you.