Bryn is an up-and-coming gentle, yet substantial, Welsh name that would also be effective in the middle spot. In Wales it's more often heard as a boys' name.
Bryn entered the U.S. girls' popularity list in 1999 but is outranked by the Brynn spelling. Reality star Bethenny Frankel named her daughter Bryn in 2010.
Trivia tidbit: Bryn Mawr college was the first institute of higher learning to offer graduate degrees to women.