During the television show Little House on the Prairie, while it was based on the real Laura Ingalls Wilder and her Little House books, the majority of the television series is quite different.
In real life, Charles and Caroline Ingalls never adopt James and Cassandra Cooper. The characters were created just for the television show.
Similarly, Albert Quinn Ingalls was not a real person either, he was also a character for the show only.
Charles and Caroline Ingalls never adopt any children in real life, nor to Laura and Almanzo.