Based on the available materials from the White Estate, there is no direct quote from Ellen White stating that "Jesus will have a human appearance for eternity as a reminder of what sin cost." However, Ellen White does write that Christ has linked Himself with humanity by ties that are "never to be broken" and that He will "forever retain His human nature" (see Steps to Christ, 14.2; The Desire of Ages, 25.3). She emphasizes the eternal significance of Christ's sacrifice and His ongoing identification with humanity, but does not explicitly state that His human appearance is specifically to serve as a reminder of the cost of sin.
**References:**
- Ellen G. White, Steps to Christ, p. 14.2
- Ellen G. White, The Desire of Ages, p. 25.3