Hello there @sathyasankar :)

Thank you so much for the re-esteem and for taking the time to share your aunt's experience here with us. I do agree with you, individual's belief systems definitely weigh in the kind of mystical of transcendental experiences they go through.

But, please note that NDEs are not to be confused with OBEs. While the latter can happen spontaneously, during bed time or the middle of the night (which seems to be the case of your aunt's experience); the latter needs to necessarily involve a near-death experience (they are prompt by an accident, heart attack and so forth).

I, myself, have had an spontaneous OBE. During bed time. I wrote about it before here on Steemit. I found rather frightening! 😅

Thank you once again.
All the best to you and your aunt!