Question about the sentence "Tiene dos hijos, Laura y Antonio."

Question

In the article on masculine gender the example given is "Tiene dos hijos, Laura y Antonio."  The translation  is They have two children... "  I thought it the verb should be "Tienen" since there are two people being referred to.  Is the example correct and, if so, can you provide an explanation?

Answer

Hola Vince
I can't see in which lesson or exercise you saw this sentence but the translation for:
Tiene dos hijos, Laura y Antonio.
should be "He/she has two children, Laura and Antonio.", not "They have..." 
If you can tell me where you saw that sentence I could check and correct if necessary.
Gracias y saludos
Inma