The question is unclear. Yet, it seems that the father of the friend of yours was petitioned five months earlier. It is not the approval date, but the actual date that the I-130 petition is filed that becomes important. The filing date is known as the priority date. The visas will be issued for those petitions that have been filed earlier. Your friend's family's application was filed earlier, so it will likely be called earlier.
The father must qualify for a visa. Sometimes, people can wait for years only to find out that they do not qualify for a visa. You and your family should consider scheduling an appointment with an experienced immigration attorney where you are confused, need more information, or want to understand whether there may be complications.
The above is general information and does not create an attorney-client relationship.