We can treat those entities as an objective reality and that is going to work perfectly fine. We can adopt any model in between. We can treat all entities as part of the client, but with an certain autonomous existence. We can treat anything as simply a chunk of consciousness units out of the vast amount of consciousness that everything is made out of. There are different existing frameworks for talking about entities.
Indian shamans use certain models and a certain terminology.
Jungians or Gestalt Therapists use other models, and so forth. Some people like to deal with entities as angels focusing mainly on higher dimensional entities hanging around to help. Use whatever model works best for the client. If she already has a suitable framework you can accommodate that. If she has been wanting to talk with angels all her life, great, that is what we will help her do then.