I don't think she holds a US B1/B2 Visa. Appointment wait time is 833 calendar days in New Delhi. https://travel.state.gov/content/travel/en/us-visas/visa-information-resources/wait-times.html. UK or EU is more suitable.So if he has day-offs (even one day), then he can drive to the Niagara falls border and meet you at the US side of the falls.