Dear Sarah,
We don’t know what God’s plan is for a specific individual. Not being able to walk could be part of God’s plan whether it is temporary or permanent.
I would urge you to begin praying the Rosary as it is a powerful pray second only to the Mass. ask our dear Blessed Mother to provide your friend the grace and courage to live their life according to God’s will. Our Mother will always help in the way that is best for us. She will bring you and your friend closer to Jesus who is the Great Healer. That way you can be assured your friend will receive much needed grace during a difficult time.
This is also one of the prayers I say and I offer it for you.
MEMORARE,
Remember, O most gracious Virgin Mary, that never was it known that anyone who fled to thy protection, implored thy help, or sought thy intercession, was left unaided. Inspired by this confidence, I fly unto thee, O Virgin of virgins, my Mother. To thee do I come; before thee I stand, sinful and sorrowful. O mother of the Word Incarnate, despise not my petitions, but in thy mercy hear and answer me. Amen