[1][4][5] She rode Ultimo, a Trakehner black horse born in 1965,[5] alongside Harry Boldt and Reiner Klimke.

In world championships, she won gold twice, also with the team, and two victories at the Deutsches Dressur Derby, again with Ultimo.

From 1980, she was a regular contributor of the trade magazine Reiten und Fahren (later part of St.GEORG [de]), and wrote books such as 60 Worte Reiterdeutsch, about riding terms, in 1979.

[5] Grillo was elected to the board of the department of dressage in the Deutscher Reiter- und Fahrerverband (DRFV) association in 1981.

[5][6] She held voluntary positions, including as member of the board of trustees of the Stiftung zur Förderung evangelischer Krankenhäuser from 2010.

[3] She was awarded the Order of Merit of the Federal Republic of Germany in 2021,[6] in recognition of her extraordinary engagement in social, cultural, trades and sports matters.