Interesting paper but her numbers seem a bit odd.
If 1.3 million women have abortions each year that would mean that each year around 1.8% of women have abortions. If you take into account most women are of childbearing age for 38 years and make the assumption that these women will have one abortion during their lifetime then 68% of women will have an abortion during their lifetime.
A billion abortions over the last 29 years in the US seems a little high. Perhaps, she needs to review her numbers.
You're right. Since 1973 over 40 million Americans were aborted.