I don't think you are allowed to sit in an exit row with an infant. Only people who can operate the doors are allowed to sit in the exit row. The infant will make it hard for you to operate the door.

If there is a chance of an empty seat next to you, then try Plane Pal or Flytot. They are inflatable cushions that fill the foot space between the seat. Note: It can only be used with the window seat, or in the middle seat of a middle section (can't block someone from exiting to the aisle).

See travel gadgets section on this page:
http://www.evaair.com/en-us/managing...ecial-baggage/