ΔE 23.6, loose: different enough that you should pick on purpose. Mummy White is a little darker, warmer than Nude Skin.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 24). Mummy White is a little darker, warmer than Nude Skin.
The same difference applies the other way round: Nude Skin is a little lighter, cooler.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Nude Skin on the colour wheel See Mummy White on the colour wheel
All matches: Nude Skin equivalents · Mummy White equivalents