I read your question carefully and I understand your concern. Generally it is recommended to wait for a couple of weeks after an endarterectomy before undertaking a flight. If it s a long flight it would be more prudent to extend that to 4 weeks, but for the journey which you mention I believe 2-3 weeks are enough waiting time. Of course her doctor knowing more about her overall condition and other diseases should have the last word on that. I hope to have been of help.