Only about 2.1 % of girls' first names in the United States begin with the letter G…
This means that the initial G is represented below average: According to this, each letter (given 26 letters in the alphabet) would appear as an initial in about 3.8 % of all girls' first names. However, the average is only a median, as initials aren't completely evenly distributed, of course. Some letters are more commonly found as initials than others. Most girls' first names in the US start with the letters A and S, while the initials U and X are the least common.