Thanks for the question.
I guess first I would like to know if the help you are seeking is for the dying mother or for the son. And which one is feeling anxious. Since I'm not sure, I'll try to address the question in general for each of them.
Additionally, I'm not sure if the dying mother is consciously aware that she is dying. Is this is being discussed with her, or avoided by the family?
If this is for the son, it's probably a good bet that he is feeling a little helpless, stressed, possibly frustrated or guilty about not being able to be with her, not to mention sad to be separated, especially at this time, and maybe grieving in advance over this impending, permanent loss. Depending on which of these conditions apply, I would recommend one or two of these guided imagery titles: Relieve Stress, Ease Grief, or Relaxation & Wellness. If there are unresolved issues that are pressing in on him, Anger & Forgiveness could be another possibility.
And if this son wants to find comfort and peace with his mother's journey from life into death, they may also want to listen to our Hospice & Palliative Care imagery, which offers a lot of solace and peace for family members as well as for the dying.
As for the dying mother, if she knows she is dying and wants to arrive at a peaceful place through meditation on her dying (either as a complement to or substitute for prayer), this same Hospice & Palliative Care imagery is a good choice for her
If however she's in denial or just not ready to address this yet, she might like the comfort and ease of Healthful Sleep. If she's in pain, she might like Ease Pain. or, if she's the one who is anxious, the Relieve Stress or the Relaxation & Wellness imagery would be good to listen to.
I hope this helps. My best wishes to all concerned.