OK there are two parts of this statement assertion... So far this statement to be true...
1. Every woman that brings forth a child first has to be a mother...
True by definition
2. Every woman that brings forth a child that is a mother must posses parenting skills.
If this hypothetical person possesses two or more parenting skills then the statement is true. I assert that for any person I can identify at least two skills that would be useful in parenting.
They might be things that some don't traditionally think of as parenting skills...
Capable of hard work.
Capable of organizing things well.
Capable of empathizing with people.
Point is no body is devoid of parenting skills and nobody is a perfect parent. Everybody has some and nobody has all.
Of course this doesn't answer the question you were probably really trying to ask which probably lies somewhere along the line of, "Should every woman who gives birth be the one to raise that child?" But if that's what you wanted to know, that's what you should have asked.
The answer is yes. For a very nice, well-explained position, refer to Zenock's post. He basically says everything that I was going to say. Basically, it comes down to this: everybody has parenting skills. Every woman that gives birth is a mother. When you put those two undeniable facts together, the answer to the resolution is yes. Every woman who had a child is a mother and every mother has parenting skills.
Has given birth to five children and hasn't raised a single one of us. Since day one she tried to buy her childrens love instead of actually bonding, shes thrown us on the street, and has only thought of herself. The only time she ever talks about us is when shes bragging about us to someone who doesnt care.
Simply birthing a child does not inherently gave a mother the skills needed to take care of the child. The abilty to to take care of a child is learned through experience. Read from books, or taught by their own mothers or family. Not only that, but not everyone is nurturing. A person, by nature, may be hard-hearted and someone cold to their own baby.
In my experiences, i feel that if a woman is not raised to be motherly she will in turn not be motherly. Yes there are hundreds of exceptions but even if there is one who doesn't act motherly that makes the above statement false. So unfortunately i have to say no.