It sounds like you had an absolutely beautiful and memorable family trip! Travelling with the whole family—especially when the kids are that excited—creates the kind of memories that everyone holds onto for a lifetime.
There is something truly special about waking up on a train to scenery you've never experienced before. That transition from the familiar landscapes of Sindh to the lush, vibrant greenery around the Samasata Junction at 6:00 AM must have been breathtaking. It's easy to see why everyone's eyes lit up! Even with the initial half-hour delay at Karachi Cantt, it sounds like the Green Line gave you a smooth, fast, and classic train journey across the country.
You also picked some of the absolute best spots to experience the depth of Lahore:
Badshahi Mosque: Standing in that grand courtyard truly connects you to the scale of Mughal history.
Wagah Border: The sheer energy, patriotism, and crowd enthusiasm there is always unforgettable, especially for the kids.
Nankana Sahib: A deeply spiritual and historic site that perfectly highlights the profound cultural and religious connections India and the Sikh community share with the region.
Exploring Lahore's rich, historic roots and then heading back home safely with a heart full of good memories is the perfect ending to a vacation. It sounds like a beautifully spent 5 days!