You got Male Green Chocobo, didn't you?

(k) The next chocobo you need to breed is Female Blue Chocobo, but you can't breed again right after you just did, so you have to spend some time.

(l) After a while, return to the farm and save. Then, repeat (j) until Female Blue Chocobo is born. If Female Blue Chocobo in't born, simply press RESET and try again.

When you get Female Blue Chocobo, click here