You can always go by plane.

of course every person is different but I think it would be doable for her.

Try to get the accommodation as close as possible to Haram. (depends on your budget).

Make up her mind that she may not be able to attend all the five prayers in Haram.

besides everything, Wheel chairs are available free of cost which your wife can use on daily basis apart from motorized wheel chair which she can use while performing Tawaf and Saii .... (I think 200 Riyal for 2 hours - not sure).

All the best.