I agree on the "et" / "ette" ending or suffix, due to the meaning.
I would consider these names synonymously, ascertaining each various form to be specific personalized preferences. Immediately below, I've copied a query I posted a few years prior when I first joined the site. During times when young, I more wondered than wanted, but partially wanted as well, why I would not have a name associated with the feminine which more closely resembled the male form
Julius or
Julian: hence I wondered why I am not
Julie or
Jill: though named for different reasons, I found these names considerably nicer or softer than my own while I simultaneously had a crush on a girl named
Julie during the nineteen-eighties; and shortly after, liked a girl named
Jill.
Probably the best known sources for the names
Julius &
Julian are from the famed
Roman emperors. Many spelling variants combine "
Julie with
Anne", with little variance from
Julian, and are frequently used to name females.
Jillian is yet another variant more exclusively retained by females, yet this variance is guarded with greater fortification - and perhaps with greater ferocity because of the "
Jack and
Jill" nursery rhyme. Is there anything wrong with the name
Jillian for a boy with the (occasional) nickname
Jill? Is there anything wrong with the (occasional) nick-name
Julie for a boy? I saw the names
Julian and
Jillian on Diet Coke bottles this week - and on a few Behind the Name texts, which led me to reconsider this - which I've considered previously.