I would stick with the 10 inch blocks. That must be the design she likes.

I vote for Disappearing 9 Patch. It's incredibly simple with a real contemporary look. Take it a notch above the plain squares in the Pottery Barn quilt. Your fab. choices are excellent! It will be a lovely quilt.

Since she has said she would leave it up to you, I would do as she said. Choose a pattern and proceed. She obviously doesn't know what goes into making a quilt. So go forth and conquer.
By the way if you decide not to use the fabrics you have, you can send them my way. They are gorgeous.

your fabrics will make a beautiful quilt and of much better quality than PB.

With those fabrics, anything you make will be beautiful.

Love your fabric's. I notice there is a really line"y" fabric in her picture which you do not have.
I might look for a line"y" fabric with a little gold or yellow in it, if you have gold or yellow in the your flower patterns.
Then I agree keep big blocks and make the quilting the pattern.

I love your fabric choices. I'm sure the bride will love whatever pattern you choose.

Norma

I think a large block D9P would be lovely with a bit of jazz in the quilting. Then you won't feel you've duplicated a
Pottery Barn quilt. Your fabric choices are wonderful!

Ask your nephew what he likes try to please him or he might know if she would like it if not maybe he's marrying for the wrong reasons. I think you are driving your self crazy. she will like any thing you do if she likes you. lol

I also love the fabrics you've chosen. Like some of the others who have posted, I'd make it as easy as possible, like the one in the picture.