That's the first female Dillon/Dylan I've seen in the
UK. It is an odd combo!
Esme was #67 on the last chart, but I've never come across any personally, of any age.
Double ns make no difference to the sound and seem to be arbitrary. Gwennan/Gwenan, Annwen/Anwen crop up regularly. Annesta, Annest, Anest and
Nest are all forms of
Agnes.