Probably the doctor sewed up the end of the vagina thoroughly and also removed the tubes, so all that is left are ovaries with no way for the egg to pass through to the vagina. Aside from the issue of having no uterus to shelter the embryo, the woman would not be able to get pregnant if there is no passageway for the egg or sperm. If she wants a baby from her eggs, it would take a gestational carrier ("surrogate mother") to carry the baby.
The uterus is what contains the fetus as they grow. I have heard of babies growing outside of a uterus but it is very risky and dangerous and even deadly to both. I would suggest a surrogate or adoption to a woman with a partial or full hysterectomy.
Yes, but the pregnancy will never be viable. You need to have your uterus to carry a pregnancy to term. If she/you ever become pregnant you will need it to be medically terminated, otherwise it can be fatal to the mother.