In my opinion, it's a good thing to go ahead and get established with an avian vet if you can - while your birdies are well...that way, they can establish a "well-bird" set of vitals, etc...so they will have that to compare to if, God forbid, something DOES happen and your bird gets sick later. It's just a good idea...if you can. Not everyone can do this, of course...money is a factor, as is whether or not you have an avian vet in your area. We're lucky here in that we have a really great avian vet who is only about 7 miles from the house. ;-)
Peeps is probably fine...like the others have said, just watch over her/him. Make sure you keep the cage covered on at least 2 or 3 sides...this makes them feel more secure. Did you put this bird in the same cage as Kiwi? It's not always a good idea to immediately put a new bird in with one who is already established...not only because if the new bird IS sick, it could get the healthy bird sick as well...but also from a stress aspect. Probably best to gradually introduce them.
Best of luck to you! Feel better, little Peeps...