No that we know of. Her husband king Ferdinand of Aragon was an avid commander and enjoyed taking part in battles since he was very young (the first time he commanded part of an army, he was 12 years old).

From a modern perspective, Isabel can be considered quite vigorous, even ferocious, but not battle-wise. She was a keen hunter since she was very young. When she was young, she spent a lot of time in the castle of Arévalo, which is close to some top notch hunting areas. When she was there, she enjoyed hunting wild boars, which she did with her trusted crossbow, a weapon she was very effective in using. She could use a boar spear too, in case it ever became necessary.

But no, she did not get in the fray of battles, where she would risk losing her life. She had her husband and many trusted generals like my lord Pedro de Mendoza, Francisco Ramírez de Madrid, Gonzalo Fernández de Córdoba, and even Beltrán de la Cueva.