Your wife i can believe. Cantonese, manadrian combo does exist and adding english i am sure it happens. But punjabi? how good is the punjabi...
I have hard time believing her sister. 5 all fluent? well i can believe A2 in several or B1 but higher than that is really really difficult. at what level? look at the chart
check out new maps i added. The reason I listed arabic, spanish, chinese, russian, and then hindi, portuguese, is because those regions of the world do not have highest amount of english speakers. You know check these links see yourself. With world becoming more multipolar i think it inevitable that regionalization happen again and english wont be the preferred. USA cannot stay dominate forever. But that another story. And yes english is only so powerful at this point globally because the US let not pretend like the UK or australia is the global power.
Even the EU which i would say globally the countries in it have highest % of english speakers. Does not have that high of % in certain countries.