Yes, That's okay for the second marriage. We come to this wonderful world to live our life happily. Unfortunately, If he/she lose his husband/ wife then are they don't have life for them? That is a curse in their life but they can change it as a boon to live a new life. Single parent has to face more problems to grow up their children. The best person to marry is one who can understand their feelings, situation and see their children as their own children. If they didn't getting married for their children? What will be happen in future? His/Her children getting married and went out with their partner by leaving alone. So, What about their condition in that situation? So, My point is they have to marry a perfect match to start a perfect life again.