Can our friend, an Orthodox Christian, be our child’s godfather?

Your friend can be godfather to your child so long as there is also a Catholic godparent and the Catholic education of your child is ensured. The Vatican document Directory for the Application of Principles and Norms on Ecumenism states:

Because of the close communion between the Catholic Church and the Eastern Orthodox churches, it is permissible for a just cause for an Eastern faithful to act as godparent, together with a Catholic godparent, at the baptism of a Catholic infant or adult, so long as there is provision for the Catholic education of the person being baptized, and it is clear that the godparent is a suitable one. (98b)

When there are two godparents at a Catholic baptism, the Code of Canon Law states that there should be one godparent from each sex (CIC 873). If your husband’s friend will be the child’s godfather, you should select a Catholic woman to be the godmother.