“If they were related by blood this could show a daughter’s admiration for her mother via mimickry.

“The two women do tend to stand and sit in the same way and their facial expressions also seem cut from the same, impenetrable cloth, but this overstated elegance and the Sphinx-like expression tendencies could also be symptoms of rivalry between a daughter and her step-mother, if one were trying to out-do the other.”

Recently, Melania was seen greeting Ivanka at the Republican National Convention with a broad smile.

However her facial expression soon changed once Ivanka had passed her to stand next to her father and the expert suggests this may be because the First Lady seems nervous at big events.