Two se[pararyte points here in this discussion thread

1. Unrelated to OP, digression into merits of Travel Insurance. Many policies will pay for Economy class return fare (whatever cheapest available at that point) Remmeber, the idea is to get you home ASAP (not necessarily in luxury)

2. QR (and EY and EK) will get you off the plane if their senior FA contacted their docotror and the doctor on the advised offloading so to the senior FA (yes, even without that doctor even seeing or talking to the patient). And on top of it they will treat you as no-show and refund ony the taxes. Now, this may depend on the consumer protection laws of the country where incidence happens. Most flights from India to ME are about 3 hours.and most such reprted cases involve children (5 to 17) range. These are no life threatening cases needing diversions to a 3 hour flight nor these are high risk to other pax type of cases. It is simply what QR/EY/EK do to pax year after year (at least in India - do not know about other Asian or African destination)
So
a) Make sure kids dont eat anything unusual on the day of travel
b) Try to suppress trivial symptoms from FA
c) buy at least the cheap travel insurance (minus the expensive cancellation part) (cost less than 25 bucks) that pays for "Return Air Only" in case of covered
interruption (it wil lalso pay for lodging/food during weathe/ATCr related delays and emergency medical)
d) carry small medical box of symptomps relief medicines and antibiotics (in most countries you can pickup strip of those for 25 cents)

OP good very good support from AA/QR compared to QR case in India where QR put the family on footpath outside airport and washed off the hands.