Yes, it is all right Gaura Nitai may wear turbans as well as crowns. You ask what they may wear in the evening - they can wear different dresses or night clothing just as Krsna is dressed. Make a small symbolical bed and give Them rest in that way. Bathe the Deities mentally by mantra and not by pouring upon them.
Letter to Gunagrahi, 20 June, 1973