bitshaken I just don't think you or your unborn child will be permanently affected by this.
You obviously have a great deal of anger about what happened, and empathy for your mum. Why not ask her why on earth she suggested that name?
You know, a lot of people who are abused in childhood do get on with life for the sake of their families. Children are born who know nothing about the past and will never need to know. It may be in her mind that it is a way of erasing those awful memories. There is nothing like a new life to make someone feel that there is a new start. It is, believe it or not, possible to like a name without forever associating it past memories which are best forgotten.
This name could signify a big step forward in your mum's thinking. It is frankly exhausting going through life with the millstone around your neck. Many people who have been sexually abused struggle not just with the abuse but the fact that other people know about it. Perhaps this is a message - if she is able to throw it off, why can't you?
As you may have gathered, I do speak from experience. It is an incredibly complex thing to deal with, and one of the worst things is people not understanding that you have actually come to terms with it in your own way, however strange it may seem to them. They expect you to never forget, but sometimes the ability to rise above it gives survivors of abuse a great inner strength.
In a way, you are raising the question ?Why would a person who experienced sexual abuse want to be close to the very people who did it??
You may find this enlightening:
www.pandys.org/articles/continuingrelationshipswithabusivefamily.html
As I said, it can be a complex and perplexing thing. But I urge you to talk to your mum calmly along the lines of "I was surprised you suggested that name" and tell her why. She might be grateful for the chance to open up to you.
Be gentle with her. She's been through enough without people judging her for not being sufficiently angry or sensitive about it.
I hope I have explained my thinking and my initial reaction to your post. I also hope you and your mum manage to get through this together and look forward to a wonderful future without anger and frustration with each other, which your new baby can be part of.