Cassandra:
Can't give you a definitive answer, but I can confuse you a bit.
From "The Odyssey of C.H. Lightoller" (1984), and "Titanic Voyager, The Odyssey of C.H. Lightoller" (1998), which are basically the same book by Patrick Stenson comes the following paragraph:
In 1907 the decision was taken by the White Star Line to open up a new route to New York from Southampton to be more conveniently placed for London, the South-East and the continental ports. This would become the principal New York service and be operated by the company's best and fastest vessels. The route included calls at Cherbourg and Queenstown.
Note the year 1907. In the very next paragraph of 'Odyssey', Stenson writes:
The change of base for the Oceanic meant a move for Lightoller, as the family, which now included a three-year-old son Roger and a second child on the way....
In the same next paragraph from 'Voyager', it reads:
The change of base for the Oceanic meant a move for Lightoller, as the family, which now included a one-year-old son Roger and a second child on the way....
So, he was probably born in 1904 or 1906. Since Charles and Sylvia were married on December 15th 1903, I would guess the year 1906 was correct, and the 'Odyssey' version was a typographical error that was corrected in 'Voyager'.