The article says the weight limit for the luggage was 15 pounds. Here in the US it’s usually 30-40 pounds, depending on the airlines.
Had they checked their baggage; the rules would have been different. The article did not say what the limit is on checked baggage.
My wife just returned from New Zealand: Carry on limit was 15 pounds and checked baggage was 50 lbs. She was gone 18 days and had no issues with the weight limits.