Is it permissible for a son or a relative to perform Umrah on behalf of a mother who is unable to travel for Umrah due to severe motion sickness?

For Hajj and Umrah (definition) to be obligatory, a person must be physically and financially able to perform the rituals. One of the conditions of ability is the possibility of riding a mount. Thus, whoever cannot ride is not obligated to perform Hajj, based on the Almighty’s saying: (Whoever can find a way there). If it is established that a woman is unable to travel due to dizziness she experiences during travel, and this condition is permanent and untreatable for her, then her son or someone else may perform Umrah on her behalf. If the mother suffers from fear and panic when riding in a car, which prevents her from performing Hajj herself, then it is obligatory to wait, hoping that this impediment will disappear and she can perform Hajj herself. If it becomes impossible for her to perform Hajj herself, then her son should perform Hajj on her behalf, because she is in the same category as an elderly person or a sick person whose recovery is not expected.