How can Umrah be performed with an elderly mother who is unable to walk, knowing that she will use a wheelchair, and is it permissible to enter into a state of Ihram from Jeddah Airport?

There is no objection to you performing Tawaf (definition) and Sa'i while pushing your mother's wheelchair, as you are not carrying her. As for entering into the state of ihram (definition) from Jeddah, it is not permissible except for someone coming from the direction of Suakin, because they do not pass by any of the two miqats before it. Jeddah then becomes their miqat (definition) because it is two stages away from Mecca. Therefore, you must enter into ihram with your mother when you are parallel to the miqat in the plane, or after takeoff if you are unable to determine when you are parallel to the miqat. The statement that Jeddah is a miqat absolutely is an incorrect opinion.