“Agents of S.H.I.E.L.D.” already has one butt-kicking female character in Melinda May, but there’s always room for one more. Bobbi Morse can easily be referred to by her old code name of Agent 19 before dropping by to lend a hand. She’s a fully trained S.H.I.E.L.D. whose hand-to-hand combat prowess would fit easily into the show’s action sequences.
On top of that, Mockingbird would give writers an easy way to make references to Clint Barton, a.k.a. Hawkeye, something they’ve already done on several occasions. Plus it would just be fun to see May make her frowny face when another woman started dishing out the pain she usually administers herself.