Rosemary can be found in most shop maps and Miranda Watty is located in Megalopolis Square.

Do not exchange character boxes with Miranda, as you'll get a 5 galder coupon. Instead, exchange with Pet Trainer Shara in Blooming Cora.

Do not risk your coupons on Rosemary's exchange. For the Simple Set, look for Pet Trainer Shara in Chaos Tower Entrance.

Source: March 28th patch notes.