How should I avoid being in the shadow of my PhD advisor after I have my own faculty position?
I find a little radical to stop collaborating scientifically with her (in part because there is no one around working on this area!), but as the time goes by it seems to me that the best option is to start working alone on this common area, or some similar solution...


There is some truth to the often-heard advise that one should stop regularly collaborating with one's PhD advisor after getting a PhD. I would argue this is doubly the case when you and your advisor work at the same place. To the outside world, you will always appear to be the "junior" in your collaboration, independently of who does how much work, who has had which ideas, or who is where in the paper author list.

My impression is that in the career stage that you are in, you should prioritize collaborations where you are the most senior person in the team, or where you are at least not overshadowed by somebody much more famous than you. Work on papers with your students, or with other people in a similar or earlier career stage than you. Avoid collaborations where you do all the work and some other eminent figure in the community (your advisor or some other senior professor) could be seen as the strategic brains behind the work.