I worked different shifts and looked after all my 4 grandchildren as soon as the maternity leave finished, so at one point I had a ( 1yr 3yr 4yr & 7yr old) from 7am till around 6pm sometimes 3 days in a row as they were from 2 different families who both worked different shifts. It was hard, but my goodness it was rewarding and never a dull moment. They bounced off each other and kept each other company, and I witnessed each of them learning skills off each other.
One of my grandchildren was really quiet and withdrawn and you'd be amazed to see them now, thanks to the interaction with the other 3. I had my special moments with them at the quiet times or all of them at the same time. A lot of cousins grow up and are not that close, but all my grandchildren who are now 8, 10, 11 and 14, are extremely close and we all have an amazing bond. They also learned a lot of lessons from each other as depending on which one got into trouble, the others knew not to follow suit. If one stood out to do something really well, the others followed suit. Yes they learned a lot from their parents, grandparents teachers etc, but what they learned from each other about sharing, depending, helping, forgiving and loving, was priceless.
I still look after all of them although the situation has changed slightly and I look after 2 and 2, and only all 4 of them occasionally. I also put in place a day every 2 weeks weeks (to let the parents get some "together time" where all my grandkids and their dog stay over at ours and we all do something fun together on the weekend, it warms my heart to see them all excited to see and meet up with each other, after they've all squeezed the life out of me running through the door, calling out for each other, absolute joyful chaos..... I love it.