Happiness is a great reason for Catholics to have large families.

I am currently reading a book called Covenanted Happiness that many here would find enlightening.
“
Couples still hope to be blessed with happiness in marriage; but they no longer seem sure about who is going to do the blessing or how it is to come about.” from Covenanted Happiness by Cormac Burke. Monsignor Burke makes a strong case that children are a major source of happiness in married love, and that large Catholic families should be the norm, rather than the exception.
Initially our spouse attracts us, and vice versa. As spouses live together, we discover unattractive faults in each other which can strain a marriage. Children help correct our personal faults and selfish tendencies. More children usually help us become less selfish and more virtuous. As spouses grow in virtue, they become more attractive to each other.
The task of raising children is a noble task that spouses accomplish together. Certainly raising a large family involves struggles, but happiness is not simply the absence of struggles. Overcoming struggles often produces greater happiness. Happiness demands effort, and the effort of raising a good family produces great happiness.
Within a large family, additional children also help the existing children to become less selfish. Selfishness is one of the greatest impediments to happiness. Those who learn to appreciate little things (which in some circumstances may be very little) are far more likely to find happiness than materialistic children who only lack gratitude.
Covenanted Happiness beautifully presents the Catholic Church teachings on marriage and demonstrates how generous married love helps us achieve and deepen our personal happiness.