Which do you like better? Also any middle names that flow nicely with either option? Thank you!!

I like Jillian better.

And I think it flows as:

Jillian Rose
Jillian Elaine
Jillian Shay
Jillian Sky
Jillian Claire

I like both of them honestly. I picked Juliana because I like the nickname Julie   Juliana Marie sounds nice, Marie is just a very common middle name.

I like Jillian.
I Juliana is cute as well.
Nameberry.com is a good website for names.
maybe that will help you find the perfect middle name.
Congrats on the baby girl  

I like Jillian : )

Thank you!