Don't get just one chicken.
I had 5 chickens, and then down to 1 chicken. I still have the 1 chicken and have finally been able to get a couple new chicks so she has friends of her own again.
She does hang with the ducks, but the ducks aren't always most welcoming of her. I'm sure she'll be happy to have friends of her own again.
I'd get at least 2 if you get them as adults, or 3 if as chicks in case you lose one before they get older.