Here’s part of her response:
Why is this philosophy and not linguistics? Well, a first point to note is that I think of myself as an interdisciplinary researcher—I read (and learn a lot from) stuff by linguists and psychologists and others, and I think philosophy benefits from having a wide evidence base and often should be informed by developments in these other areas. Secondly, there are a lot of linguists who do very much the same kind of thing I do (like Deirdre Wilson and Robyn Carston, to name but two), so I also think that asking about which discipline something belongs to in these borderline areas is a bit invidious—if the work is good, I guess I don’t really think it matters which department someone sits in. Thirdly, though, having said all that, I still do think of what I do as philosophy and not as linguistics and it does matter to me to be amongst philosophers. There is a general way of thinking about things—of asking questions and looking for answers—that is, I think, special to philosophy and it’s what I love. When I started at the University of Reading the department had a strong ethics orientation, but all the ethicists were willing and very able to interrogate my work because the way of going about things (at least in analytic philosophy) is broadly the same, whatever the precise topic. Also the kinds of questions I’m interested in come before many of the questions in linguistics really get going. So, for instance, the above question of what we need a theory of meaning for isn’t something you’ll find much discussed in linguistics.
This answer nicely captures the ambivalence I suspect many philosophers have about the boundaries between philosophy and other disciplines: difficult to delineate and possibly a hindrance to good scholarship if taken too seriously, while nonetheless marking off a “special” way of thinking that personally matters, characterized to some extent by open-ended, general, and fundamental questioning.
The whole interview is here.