Mashallah, You're welcome rizwan.
I think marriage and all it entails is also for those who wish it and are capable of adhering to its policies. Although there are some people who never marry, either by choice or some other reason. Imagine if no one married and procreated...no population!!! Women who are barren are still mothers, even if it is not their own child/children.
Is marriage not valid if based on love even if two people don't create their own children?
Allah says in the Qur'an that He leaves some women barren, but that is not the reason for them to not marry. There are many women who cannot have children for one reason or another. There are women who are told that they will never have children and later on have a child.
Marriage is much more than procreation, acceptance of an infertile mate is for the two people to decide. There are many couples who have adopted and are happy about their decision. Remember that marrying a person(woman) is based on:
2. Finances3. Deen
4. Family status
But of these deen(religion) is the best choice. It does not say anything about the woman's fertility/barrenness, Mashallah. A women can have all these things and not be a good muslim and barren.Adoption In Islam
Adopted children become mahram for their child by way of suckling(if the child is an infant). However here is a bit more info that may help in understanding adoption:
"The guardian/child relationship has specific rules under Islamic law, which render the relationship a bit different than what is common adoption practice today. The Islamic term for what is commonly called adoption is kafala, which comes from a word that means "to feed." In essence, it describes more of a foster-parent relationship. Some of the rules in Islam surrounding this relationship:
An adopted child retains his or her own biological family name (surname) and does not change his or her name to match that of the adoptive family.
An adopted child inherits from his or her biological parents, not automatically from the adoptive parents.
When the child is grown, members of the adoptive family are not considered blood relatives, and are therefore not muhrim to him or her. "Muhrim" refers to a specific legal relationship that regulates marriage and other aspects of life. Essentially, members of the adoptive family would be permissible as possible marriage partners, and rules of modesty exist between the grown child and adoptive family members of the opposite sex.
If the child is provided with property/wealth from the biological family, adoptive parents are commanded to take care and not intermingle that property/wealth with their own. They serve merely as trustees.
These Islamic rules emphasize to the adoptive family that they are not taking the place of the biological family -- they are trustees and caretakers of someone else's child. Their role is very clearly defined, but nevertheless very valued and important."[Taken from.Huda.com "Adopting a Child in Islam
There are a lot more point of understanding about adoption, just have to find it, Inshallah!!