No issue with this.
Living in India most of the year my children are exposed to spicy food all the time.
The only viable reason for them to not to eat it, is if they dont like the taste.
My son hates it, my daughter loves it.
there is a huge difference between spicy food and vindaloo.
well tbh vindaloo is made differently from place to place however it's meant to be a lot spicier than a madras which is what i would classify as spicy.
i eat more spice than the average person but even i wouldn't touch a vindaloo, it's just a base curry sauce with hundreds of chilli in it, it tastes horrible.
give the kid a full green chilli, the little birds eye ones and make sure it's fresh, not the big jalapeno style they are too weak. if they can eat said chilli raw within 30 seconds then they can have a vindaloo.
however i would recommend if they can handle it to order a speciality dish like a south indian garlic chilli or an achari and just ask the chef to throw a lot of green chillies into it. so you get the same heat level of a vindaloo but at least it has some flavour.
Its possible.
For me spice overpowers any flavour, but my 5 year old daughter will sit and happily work her way through a selection of raw green and red chillis.
For me its absolutely horrendous, but for her.....she likes it.
what chillis though? some aren't that spicy at all. well not really.
i can eat them raw too and been able to do so since probably early teens, maybe even younger it's not something i made a mental note of.
some chillis can be really weak and you can eat a lot, then you hit a fresh ripe one and it blows you away.