find child

My cousin is married to a guy who is an international sales executive and he was having an affair in South Africa with a citizen and he may have fathered a child. All thats known is her name and her mother's name. Is this enough to find out whether or not she has a child. What are South Africa's most difficult laws on this matter. She doesn't want her children to be confronted with this latter in life, if something happens to either of them. She is a mother of four and she just wants "peace of mind", he is completely closed to the matter. Please help her, she's a great mother and wife. The woman may also be living in Germany.

thanks