From All Is Happiness (#E-60) by Rabbi Avigdor Miller
Raising a big family is a very difficult thing.
The Gemara says a person who has endures tzaar gidul banim (the suffering from raising children), “aino ro’eh p’nai Gehinom — will never see the face of Gehinom.” She won’t go to Gehinom, even for a short visit. She had enough “purification” in this world; she suffered from house full of children. You have to take care of this child, and give in to this child, and cope with this child… and sicknesses and fighting... all kinds of problems. When a mother brings up her big family, no question it’s a life of difficulty.
She's enjoying each one, because her troubles are also her hatzlacha
But then you have to know there's no such simcha (happiness) as the shleimus, as the achievement, of bringing up a house full of bnei Torah. There's nothing in the world that can compare to it. She's like a rosh yeshiva; that’s her perfection, that's her happiness.
So even in the midst of her troubles, she stops and thinks, “Baruch Hashem, I have children! Look how many women don’t have any children! And baruch Hashem all my children are normal; look what happened chalila, to other people! And baruch Hashem, they’re all going bderech hayoshor (along a good path). Baruch Hashem!"
Despite the difficulties, she's enjoying that. She's taking opportunities that present themselves for happiness. So the happiness and the troubles are interspersed; now troubles, now happiness, now troubles, now happiness. But she's enjoying each one, because her troubles are also her hatzlacha (success).
And the happiness! She sings to Hashem! And finally, when she raised up a big family, and she starts seeing grandchildren, all bnei Torah, then she should sing and sing. The older you get, the more nachas (pride) you get from your children, and you have to sing more and more to Hashem.