It won't be that much of trouble. Direct flight to India will have hindi speaking air-host(ess) for sure. In Delhi, I think, everyone understand hindi. And for KTM, hope they haven't forgotten nepali

Well, on serious note, pre-order their meal. You can call airlines or on their website. I believe, with permission from airlines ticketing counter you can escort them up to the point where they board their plane. You need a security pass from airlines, I think.