What kind of irony is displayed in a thousand splendid suns?

It's ironic that even though Mariam cannot have kids, she "adopts" Laila and Aziza as her own. It's also ironic when Jalil blesses Mariam with many children when she cannot have any of her own. When Mariam is first married to Rasheed, he tells her she must wear a burqa, for purity. Yet he owns dirty magazines of other women and sisters.