Tell your friend that she is absolutely right - that we should not force our beliefs on another person.
Then remind her that the unborn baby IS a person, and when a mother decides that baby is not worthy of life, SHE has imposed HER beliefs onto that person.
So, really, saying that you should not impose your beliefs on another person is an argument FOR the pro-life side, not against it.
Also, and I don’t have time to dig up the sources for this now, women who have had abortions versus women in crisis pregnancies who kept or placed their baby for adoption, are something like seven times as likely to commit suicide.
There are other troubling statistics, too, about what abortion does to a woman’s mental health.
So, why should we allow a procedure which, by its nature, leaves one dead and one injured? isn’t that simply irresponsible? What other medical procedure is allowed that would leave one dead and one injured? At some point, this is a public health issue, a women’s health issue.
If we really care about a woman’s health, we’d outlaw abortion.