Since she wants the BSR she's going to have to go with a Bernina :> Just putting that out there to those who try to talk her out of it. I own many different brands of sewing machines and Bernina is by far the highest quality machine on the market. If cost isn't a huge factor, I'd go with the 730.
I have the 830 and 9mm stitching. No problem finding the 1/4" sweet spot!