Is there any mention of child adoption in any Buddhist writings and what is the view on child adoption with regard to Buddhism?

Being married, I have of late been coming across the dilemma of whether to have a child or not and if yes, if a biological child or not (which by itself may be another question which I may ask separately). So, when I ponder on the subject, I get the thought if it may be more meaningful to adopt an orphaned child instead of having a biological child. But again, although at the surface adoption appears to be an altruistic and more meaningful thought, if I think deeper, I really wonder if the desires as a result of which I would want to have a biological child (and which I want to avoid) are pretty much the same as those which want me to adopt one. Additionally, adopting a child has its own administrative and emotional complications, which may result in unhappy experiences and which may therefore defeat the entire purpose. So, I thought it may help me build a perspective on the subject, if I come to know what is the opinion on child adoption with regard to the Buddha's teachings. So, my questions are:- 1. Is there any mention of the merits/ demrits of adoption in the Tipitika or any other Buddhist writings? 2. Is there any incident from during the life of the Buddha in which child adoption was involved? 3. Would it help to strengthen one's ethics by adopting a child? 4. How can we compare or weigh the merits of dana to several orphan children vs adopting and nurturing one?