The suspension of the enforcement of a return order under the Hague Convention on the Civil Aspects of International Child Abduction and EU law, as well as the admissibility of modifying such an order, remains one of the most sensitive matters in cross-border family disputes. The article analyses EU Council Regulations 2201/2003 (Brussels IIa) and 2019/1111 (Brussels IIb) in terms of the objectives set by the EU legislator: strengthening the protection of the interests of the child and mutual trust of Member States in their justice systems. The text also refers to Polish law as an example of the evolution of the approach to the analysed issues. It presents its development, highlights the solutions concerning the competences of the Ombudsman for Children, and provides an assessment of the current legal situation in the context of Brussels IIb.