Question: Best way to launder antique christining gown?

I have a cotton christing gown, about 80 years old. It is hand made, in good shape, detailed, and depicts the traditional Southern style from that era. I want to gift this to my niece who is expecting her first baby around the end of January 2014. This gown is a family heirloom, so it is very special. Any suggestions greatly appreciated as well as any interesting tidbits you may have to offer. I wish to launder it without messing it up, make it look clean and presentable. Many thanks for your input.