Abortion was legalized in Colorado in 1967.
http://en.wikipedia.org/wiki/Abortion_in_the_United_States
Moreover, this woman is from an affluent family and there have always been private doctors that broke the law and performed abortions, and there were many European countries that allowed it at the time.
I just think that either setting it later or setting it somewhere it could have actually happened will make for a more believable, and therefore more effecive, story. Setting it in Colorado is a great idea! Maybe she could throw in an case of breast cancer to underscore the tragedy?