Unless you are seeing a robot instead of a person, that can't happen. People, therapists too can't turn relationships of any sort on and off that way. You have changed your therapist's life by being her client. She is learning new things, thinking new thoughts, becoming a "better" person/herself more by seeing you.

We just can't see into other people though, so forget that what is happening to us, happens to other people. No, your therapist isn't experiencing exactly what you are at this time, that's because you are two different people in two different lives and places/experiences. But if you were a therapist; what you would be experiencing would be similar to what she is. Just as when you leave the therapist you will still remember her/what you thought and felt and learned and experienced relating to her, she will do the same in relationship to you. True, she has more clients than you have therapists so it is more like what a teacher in a one-room schoolhouse might experience each year :-)