Is she obligated to report that rape? Is she obligated to accuse someone? Is she obligated to prove she has been raped? Is she obligated to cooperate with an investigation into her rape? Is she obligated to even claim she had been raped?
The answers are “No, No, No, No, and No”. Since she is not and should never be under any sort of obligation to do any of these things, you don’t know and can’t know that she was raped. Yet, by your argument, as a victim, she is entitled to an abortion.
With your philosophy, you could presume that any particular woman seeking an abortion has been raped, and is simply not reporting it for whatever reason. She is entitled to her abortion.