[quote="aicirt, post:3, topic:204872"]
Don't know about that. My Mom's godparents were both Protestants and they were the witnesses at her parents' Catholic wedding.
Our son has a Protestant godfather who has been a wonderful and faithful "uncle" for son who is now middle age.
That man's brother, also Protestant, served as godfather to his children who were raised Catholic.
sanctareparata is right. Canon Law is clear that only a Catholic (one who'd been Baptized, Confirmed and received First Communion and in good standing) can be a godparent. A non-Catholic, baptized with the Trinitarian formula and water, can be a Christian Witness. And unless I'm mistaken, that's only been allowed with the change in Canon Law in 1983.
DS2, baptized in 1984, has a Godmother and a Christian Witness instead of a godfather -- that doesn't mean that we as a family don't call the man his godfather or that he can't be a great role model (in our case he isn't but that's another story). In fact, the difference wasn't even explained to us by the priest at the time. I only found out about the difference about 18 years after the Baptism. It makes sense,though, since Canon Law doesn't use the name 'godparent' but 'sponsor' and you can't sponsor someone into a Church/club/organization to which you don't belong. In some parishes I know,the CW's name doesn't appear in the register or on the Certificate of Baptism.
In your mom's case I wonder if the priest even asked.
I say that because I'm aware of a few cases in my own parish where 'godparents' turned out to be non-Catholics, not because that's allowed but because Fr. had assumed they were Catholic and never bothered asking the question. It created problems when the family presented the next child for Baptism and were greatly offended to be told that only a Catholic could be a godparent. They thought we'd pulled this "rule" out of our hat and were so angry that they opted not to have the child baptized until 5 years later after I published a thorough explanation of the requirements for godparents in the parish bulletin. There was a knock at the office door the next morning and Dad asked to have Joey baptized as soon as possible.