If by going to "public places" you mean places like the mall, pet store, etc., then I would have two concerns:
*The first would be getting diseases from walking & licking areas on the floor, (also bird poop on the sidewalk carries infections dogs can catch).
*The second would be her ability to know how & when to hold it and not "go" on the floor.
*My only concern about playing out on the grass would be the fleas & ticks.
My Vet was also very adament about not letting Charlie walk around past our property until all his shots were given.
Charlie (Cav - 11 Mos.) and Michi (Siamese -12 Yrs.)