We call our Jillian "Jilli" as a nickname, but Jillian most of the time.
Same here. Our Jillian is Jillian and she will correct anyone (including DH's aunt) when they call her Jill. We sometimes call her Jilli/y as in JilliBean or SillyJilly but never write it this way. Honestly, I call her MissBean, Pumpkin, or Honey more than I call her Jilli.
Like PP have said, we get lots of compliments on Jillian.