Halacha: Sources of Comfort for Childless Jews
Halacha does not require women to have children:
A man is commanded to procreate but a woman is not (Rambam Ishut 15:2 and Shulchan Aruch Even Haezer 1:13).
But women, some more than men, grieve over not having children. The prophet Isaiah consoles us: "Let not the barren one say, "Behold, I am a dry tree...I will give them in My house and in My walls a place and a name, better than sons and daughters; an everlasting name I will give him, which will not be discontinued. (Isaiah 56:3,5)
The commentators explain: Because the soul is lasting in its own right, even without a parent or child (Malbim 56:3). On Har Habait where the Temple is located, there sit the courts and the elders, and there he will be given a place and a remembrance. To say that there he will be remembered as good and it is better than the remembrance that comes from sons and daughters (Metzudot David 56:5).
This same idea of good deeds being our children is found in the book of Genesis:
These are the generations of Noah; Noah was a righteous man he was perfect in his generations; Noah walked with God (Genesis 6:9).
Rashi explains: Another explanation [for why the names of the children are not mentioned immediately following "These are the generations of Noah"]: To teach you that the main generations [progeny] of the righteous are good deeds (Midrash Tan. Noah 2, Rashi Genesis 6:9)
Halacha says that we are parents if we have students. The source for this is in the book of Deuteronmy:
And you shall teach them to your sons (Deuteronomy 6:7).
Rashi and the Talmud explain: These are your disciples. We find everywhere that disciples are termed "sons," as it is said: "You are children to the Lord your God" (Deut. 14:1)...So too, we find that Hezekiah taught Torah to all Israel and called them children, as it is said: "My sons, now do not forget" (II Chronicles 29:11). And just as disciples are called "children," as it is said "You are children to the Lord your God" so too, the teacher is called "father." (Rashi Deuteronomy 6:7). Anyone who teaches the son of his fellow person Torah, scripture considers him as if he gave birth to him. How do we know this? Because the Torah says, "These are the generations of Aaron and Moshe" (Numbers 3:1) But immediately following this, it says, "These are the sons of Aaron..." So why are they called both the sons of Aaron and Moshe earlier? Because while Aaron bore them, Moshe taught them Torah. Therefore, they are called by Moshe's name." (Tractate Sanhedrin 19b)
And, finally, Halacha acknowledges that we can be parents through adoption. The source is in the book of Samuel II:
And Michal the daughter of Saul had no child until the day of her death...And the king took the two sons of Rizpah the daughter of Ayah, whom she bore to Saul, Armoni and Mephibosheth; and the five sons of Michal the daughter of Saul, whom she bore to Adriel the son of Barzillai the Meholathite (Samuel II 6:23, 21:8).
From Rashi and the Talmud: Now did Michal bear them? Did not Merab hear them? We conclude that Merab bore them but Michal raised them and they therefore were called after her name; for one who raises an orphan in his house is as if he had begotten them and he is called after his name.(Rashi Samuel II 21:8) This teaches that whoever brings up an orphan in his home, Scripture ascribes it to him as though he had begotten him (Tractate Sanhedrin 19b). The one who raises [the child] is called the father and not the one who gives birth [to it] (Midrash Exodus Rabbah 46:5).