Her own brunette locks are never less than perfect. So Princess Mary shared her expertise with a group of young fashionistas in Rio de Janiero.
The royal's Brazilian tour took her to the Cidade de Deus (City of God) favela where she was treated to a fashion show by local youngsters.
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Presumably helping out with the preparations beforehand, Mary wielded a hairdryer as she got hands on with grooming one girl's hair.
Behind the fun, Mary was there for a good cause. The brunette wanted to experience for herself the social projects that run in Cidade de Deus – one of Brazil's most high profile favelas, which welcomed Barack Obama in 2011.
Later in the day she joined forces with her husband, Crown Prince Frederik, who had been promoting Danish and Brazilian trade.
The royal couple have a legendary rapport when they carry out engagements abroad, and always ensure there are smiles all round.
This time, they made memories at an inaugural exhibition for Danish design company Fritz Hansen.
Frederik looked amused as his wife took time out on one of their colourful chairs.
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It's a little princess!