Whether or not someone can have an abortion is completely up to the person who is going to have the baby, and this is the main point that these people debate. So I think that their ideas are credible and valid, and that they have some good points they push.
When it comes to right wingers talking abortion, the logic is always flawed and packed full of religious nonsense or personal biases that or wrong, or medical opinions that aren't valid. They say things like right to life, then want to take programs like food stamps away. I can't listen to them on this subject.
Given the information available on Wikipedia regarding Rachel Marsden and her way of handling her personal relationships, I wouldn't find anything she said credible. She has spent time on probation for the criminal harassment of an ex-boyfriend and also identified another ex-lover as an informant regarding terrorism. She has also outright expected Wikipedia to delete her page because she felt it was libelous. When her relationship with Wales (a Wikipedia co-founder) was ended, she put a t-shirt on eBay with white stains on it that she claimed were Wales. Marsden's way of handling business hasn't done anything to help women and she certainly shouldn't be held as an authority on anything.
I personally think that abortion rights are not credible because I personally think that if an individual lay down and had a child that individual should raise that child. I personally think that abortion rights are not credible because I believe that having a child and then turning around to abort it is very terrible on that individual.
No, right-wing idealists like Rachel Marsden have no credibility on abortion rights. Right-wing idealist are just extremist. Extremist have no credibility due to the fact that they do not understand that not everything can be exactly how they say it should be. They do not understand that there is more than one voice.