According to "Lydie's Legend, E.W. Marland's Tragic Love" by Patti Apman (1995), George Roberts was born on November 19, 1897 and Lydia (called Lydie) Miller Roberts was born on April 20, 1900 in Flourtown, Pa to George Frederick Roberts and Margaret Collins (Mary Virginia Collins Marland's sister). On that page in the booklet is a photograph of young George, Mrs. Sam Collins (Mary Virginia and Margaret's mother), E.W. Marland, Lydia and Mary Virginia.
Later, two more children were born to George and Margaret Roberts, Virginia Roberts and Ernest Marland Roberts. George, Sr. is mentioned as a pushcart peddler and there really isn't much substantive information about him.
In any case, the Roberts apparently didn't make a lot of money and like many people in similar situations during those times, farmed out some of the children to more well-to-do relatives. George, Jr and Lydia/Lydie went to Ponca City, Oklahoma in 1912 to visit and never went back home to Flourtown to stay. They were officially adopted by the E.W. Marlands in 1916.
Mrs. Marland (Mary Virginia) died in 1926. In 1928, Mr. E.W. Marland went back to Flourtown to have Lydia's adoption annulled so he could marry her that same year. Their wedding took place in the Roberts home there.