Arrive in London and settle into a family-friendly hotel such as Premier Inn London County Hall, which offers easy access around the city and cribs for babies.
Board the Eurostar train at St Pancras International to Gare du Nord, Paris. The 2h20m ride is smooth and family-friendly with priority boarding for families.
Take the Thalys or similar high-speed train from Paris Gare du Nord to Amsterdam Centraal, approximately 3h20m. Family priority seats may be requested.