My wife feels detached after deep visualisations; is this dissociation affecting her mental health?

My wife has a rigorous deep visualization style and occasionally when she emerges, she is totally disconnected with her body and reality. It is like it is uncomfortable and disorienting and takes hours, she says. I am concerned that this dissociation is having a toll on her psychological well-being and augmenting her underlying stress. Her name is Shalini, DOB is 7th February 1989. Can she not have profound imagery?