I replaced my passport last year also because it had a small 4 mm tear in the photo page. Never had an issue as i don't think it was ever noticed but all it takes is one person to see it and then the show kicks off, it bothered me as I have heard of passports being denied because of tears. The airline staff did as there instructed, if IndiGo allowed her on the flight and India immigration denied entry the cost is on the airline to return her to Thailand. Also if an airline gets to many rejections of passengers due to paperwork that shouldn't have been allowed, then they get fined. So, as cold as it may seem she has to either get a new passport or book a direct flight, or book on another airline and try again and hope they don't notice. Its not polite to talk about people's finances but it seems she doesn't even have an emergency fund even though she has traveled to several countries, not really the best plan. And for the sister to open a gofund me for such a small amount? It seems the whole fam that has bad financial planning if that's what is
needed to help her.