Noise canceling is key! Does she want wireless or wired? We bought a pair of JBL headphones last year and I have to admit that they are great! I did not really even know the brand when we bought them.
Any headphones made in this era that don't have the noise cancellation feature is as good as nothing. I mean that feature makes a whole lot of difference especially for those who makes use of the headphone in the studios. I've used some headphones from JBL in the past and must say that they are very good at what they do.