13.Qb6# is a quicker mate.
Fixed it. (I didn't notice that there was a better one for black)
1. Qe5+ Ka7 (1.....Kc8 2. Qc7#) (1.....Kb7 2. Qc7#)
2. Qc5+ Kb8 (or Kb7)
3. Qc7#
Fixed