Actually, I thought at the time, how easy it would be to steal a three year old and get away with it, especially in a country where the child couldn't understand the language spoken.
I hasten to add that I have never wanted to steal anything and certainly not a child.
But here is the pure realm of fantasy scenario.
Provide yourself with a backpack, trekking boots etc. and make out that you and friend are walking to Fatima and afterwards to Santiago de Compostela in Spain as pilgrims. Plus a passport for a child of the right age, who you claim is your child or grandchild.
Buy a change of clothes for the child and henna to change her hair colour. Kidnap child, change her hair colour and clothes and set off towards Fatima. Behave like ordinary tourists or pilgrims. Continue towards Spain and cross border on one of the pilgrim routes.
You are highly unlikely to meet either a border patrol or the police.
If questions are asked, you are looking after the child for a few days, while her mother is ill and her father away on business.
Until corona closed the borders you could literally cross any border within the EU without seeing a border patrol. I have personally crossed the border from Portugal to Spain, Spain to France, Belgium to The Netherlands and from there into Germany, without meeting anyone who wanted to see documents.
From my house in S. Denmark I can show you four separate routes into Germany, where I assure you there is rarely a control. If the police are there, you just turn round and walk back the way you came.