[2] In parliament, Valero served as the green coordinator in the Security and Defence Committee (SEDE).

She also served a member of the Committee on Civil Liberties, Justice and Home Affairs (LIBE) and the Delegation to the ACP-EU Joint Parliamentary Assembly (DACP) and as substitute in the Committee on Foreign Affairs (AFET), the Delegation for relations with the countries of Central America (DCAM) and the Delegation to the Euro-Latin American Parliamentary Assembly (DLAT)[2] In addition to her committee assignments, Valero served as vice-chairwoman of the European Parliament Intergroup on the Western Sahara.

[3] Valero works with the rights of refugees and migrants and for legal roads in the EU.

She advocates an open and humane migration policy and has criticized the EU's Migration Policy Agreement with Turkey, in favor of Member States sharing responsibility for refugee reception.

Valero has been committed to minority rights, including Kurds, Assyrians / Syrians and Romans.