I'm looking to upgrade my wife's Raleigh Superbe 3-speed to a hub with a wider range/more gears. We live on top of a hill and the range of the Sturmey hub doesn't quite cut it for her.

The only problem is that the bike has 114mm rear dropouts. It's steel so obviously it can be spread, but going to 130mm would be pretty extreme. Are any of the 7- or 8-speed hubs available in a narrower spacing?