If you can send a pic of what she has now, I might be able to give you a couple of ideas.
In the past, it used to be Saucony, who were noted for their narrow heels and wider forefoot. The current batch of spikes they are producing seem narrower up front than in the past, though. That's a problem.
I had a miler about 10 years ago with a similar issue; she found one of the cheaper Nike shoes was fairly wide up front. We took a razor to what was then the leather support straps in the front of the shoe, cutting away first the stitching, then the leather from the area around the bunion. It worked for her.
One problem we would run into now is so many of the brands are using impressed plastic strips that cut across the forefoot of the shoe. They would be difficult to cut away, as they are embedded in the fabric (instead of being just stitched over the top, as they used to). Look for shoes that DON'T have those (like some Nike models); she may find one that doesn't put pressure on her bunion, as our girl did.