I certainly wouldn’t risk using up your knees before starting for home.
Why do I get the feeling that tomorrow’s punchline involves calling a taxi to avoid the 3 hour walk BACK?
Maybe they should have walked to somewhere that does not involve shopping.
3 hours one way, 2 hours in the mall, 4 hours back. One way to fill a day. Tomorrow will be tending the resultant pain.
Better not buy anything, because they will need to carry it home.
When in Vancouver, B.C., we decided to get some poutine. The hotel map showed the place being 12 blocks away. Except there was no scale and it was actually 12 km. Lunch was great and we took the bus back.