while she might need to recheck the luggage, she should not be charged for customs. i've never heard of anyone being charged for import taxes on transit. besides, the goods are not for use in india (not being imported to india). if they charge customs for goods, then they're trying to loot you. what items btw? one laptop, one camera, one dig cam, one mp3 player, one phone, etc personal to the traveler is usually never taxed, even on the country of import.

for the long transit, give her 20-40$ and tell her to get the business lounge for overnight sleep. i think it costs 20-25$.