Ummm...just from a strictly technical medical standpoint, you don't generally go from fertile at 28 to infertile at 34, so her argument that you robbed her of her fertile years is just hooey. And I'm interested to know just what kind of workup she had (was she trying to get pregnant now with a boyfriend???).
They might have told her she has some condition like PCOS which makes it HARDER to conceive, but certainly not impossible. Or she could have picked up an std (like chlamydia) from someone that CAN lead to scarring of the Fallopian tubes, but you wouldn't know if it had done that unless you did a special test of the uterus (which usually wouldn't be done except as part of a big infertility workup).
So - I GUESSING that what she was told is that she has some condition which may make it more difficult to conceive, and she's jumped directly to "she's infertile".