Source for Margaret Sanger's apparent ok on *legal* abortion?

[St_Francis]

I have read in a couple of places that Margaret Sanger was not against abortion, per se, only against the type of back-alley abortions she had witnessed the effects of; and that she was for “safe” abortions.

I cannot find a source for this belief, despite the fact that one place I read it was pro-abortion, but I am interested in finding one.

Thanks!