"Blend of Emma and Lynn"
The name Emmelyn is commonly a female name.
Emmelyn is a modern English-language formation built from Emma plus the -lyn ending, the same pairing that produced Emmalyn. The -lyn element closes many modern girls' names in English, such as Madelyn and Brooklyn, where it derives from the name Lynn. The name is not attested in United States birth records before 1999, which fits a twentieth-century coinage rather than an inherited name.
The pronunciation of Emmelyn is EM-uh-lin.