As the only child of my father  I have a great deal if responsibility over my  siblings, either biological or adopted
Wow,I understand the demands on you
term "only child" is generally applied only to those individuals who have never had siblings.
OK,what other responsibility do you have?
Only child
An only child is a person with no siblings, either biological or adopted. 
Children who have half-siblings or step-siblings, either living at the same house or a different house - especially those who were born considerably later - may have a similar family environment to only children, as may children who have much younger siblings from both of the same parents (generally ten or more years).
Overview.
Throughout history, only children were relatively uncommon. From around the middle of the
- Valanice: The queen of Daventry makes only a brief appearance, but what else would you expect from a mother who has lost a child only to have the other be made a sacrifice?
- Graham: The king of Daventry has been through a great deal, but it seems there is little he can do about the dragon terrorizing his realm. If only he had an heir that could take up where he left off. Josh Mandel (the developer-producer of "King's Quest I: Quest for the