That's an interesting question. Of course it is up to you, but here are some ideas:
Female "pen", male "cob".
They are known as Cobs
A good baby swan name would be something representing its meaning. Marali means Swan in Sanskrit, so Maralika means Little Swan. Amise is Hebrew and means Grace. A swan is a very graceful creature. Sangita is Sanskrit and means Divine Music. The swan is often said to represent music and beautiful singing.
COB
a female duck is a hen a male duck is a drake.
A male swan is called a cob.
A female swan is called a 'pen'; the male is a 'cob' and as you know, the babies are 'cygnets'...
swan and a cob
Cob's the name for a male swan, pen for a female. A group of eggs, or baby swans, is ka a clutch. The general term for all baby swans is cygnet. The word comes to English, from the Latin cygnus for swan, by way of the French cygne. The scientific classification of swans is kingdom Animalia; phylum Chordata; class Aves; order Anseriformes; family Anatidae; subfamily Anserinae; genus Cygnus.
If you are talking about the princess who is turned into a swan then you are talking about Odette. Her male lead and prince is Derek and the evil guy is Rothbart. =]
A cygnet is a baby swan. A male swan is called a cob.
The female swan is called a pen and the male swan is called a cob.