Welcome to the boards.
With the name I was able to find a picture via "Eileen Wright Infinity" as the search term.
What I usually do enlarging patterns is count the number of rows/squares -- this is quite a bit more complex as the rows vary in width... But I would start there by counting the number of rows. If you added just 1/4" to each piece (both vertical and horizontal) with all those seams it would change the design a bit but still give the overall effect and most of the size you want.
I think the easier idea to make it larger would be to add a border using the outer curves of her design where it forms the V, I think 3 of those units per side would work -- you would also need to figure out how much background it would take so those would fit nicely. I'd probably just use corner squares of the background and not try and make the design meet.