Guardian for my kids for a short time

My wife was extremely critical for 3 months early this year, now she is stable, but not able to walk and breath properly yet, so she is undergoing treatment in India.
Now, I have to go to India to bring her back. The total travel duration would be 3 to 4 days ( From leaving Schiphol to arriving at Schiphol with my wife).

I would like to leave my minor children with my friends family, because the travel cost is too much to afford. I want to know how can i do this legally, basically covering the below 2 scenarios.
1. If there is some accident/illness happens in Netherlands involving my kids, my friends family should be able to take care of them as legal guardian.
2. In case if I and my wife die/not able to travel back to Netherlands, my friends should be able to bring my kids to India and handover them to my parents/us respectively.

I and our kids are Dutch citizens, my wife is holding Indian citizenship with dependent Dutch resident permit.

Could you please help us how to cover this legally. Awaiting your response.