About 4.1 % of all girls' first names in the United States begin with the letter R...
This makes the initial R a little more common than average. On average, each letter appears as an initial in about 3.8 % of all girls' names, given that there’s 26 letters in the English alphabet. Of course, first letters aren't (exactly) evenly distributed as initials: On the contrary, some initials are especially common, while others are really rare. The most common initials among girls' first names in the United States are A and S, while fewer
girls' names begin with the letters U and X.