Someone asked me in a comment, what is my role in all this? Good question. I am not at all close with Aunt but I am close with my cousin (son of Aunt) and he needs help to keep his mother and mother-in-law peaceable. Unfortunately, he is a member at Stack Overflow under his real name and he feels vaguely disloyal to his mother to ask this question here himself. Call it Indian Sentiment, but it's all right because I have sent him the link and he will read all your advice himself, to help him act as an effective mediator and quickly resolve this interpersonal conflict!
My aunt has gone to the USA to visit her son who emigrated in 2007 and has recently married an American girl (not of Asian origin) whose family belongs to California. My cousin and his wife live in LA and her parents live nearby in the same city.
Aunt entered straightaway into a misunderstanding with her daughter-in-law's mother, and this rather famous type of Indian traditional rivalry was precipitated by an incident involving a cat whose name is not Kitty.
My cousin had got married in India in 2015 and the bride's parents did not bring their cat. So my aunt was aware of it but had not yet met this pet. She has no experience of cats and nor do I -- most cats in India are feral and very independent beasts and Aunt's sole previous pet was a little dog named Roger (name changed to Tinky after a famous sportsperson of the original name rose to justified greatness in the mid-2000s; Tinky is now 15 and lives with Aunt's daughter in Bangalore.)
Incident: When Aunt visited her in-laws in LA she pounced upon their cat and gathered it up into her arms saying O Kitty Kitty -- the cat apparently spat in her face (which may be an exaggeration that Aunt isn't incapable of) and scratched her nicely. Do cats resent being called 'Kitty'?
Now Aunt and her daughter-in-law's mother are embarked upon the Second Cold War. Aunt blames them for 'snaring her son' for whom she had been lining up prospective brides in India; and the son's mother-in-law (who might as well be called Alice) considers my aunt a reckless and stupid person who doesn't even know how to approach a pet. She has no negative attitude to my cousin's marriage but finds his mother a handful. Her husband Tom does nothing but play golf. Aunt blames Alice for her getting scratched:
Indians consider a guest as next to gods but this person allowed her cat to scratch me.
The scratch is deep and I have seen its picture on whatsapp. It is healing well enough. The cat has ignored my aunt after this incident.
(Related question: Should I always ask a dog owner before I pet their dog?)
@Kat has asked in comments:
Why do Aunt and Alice need to interact at all? Is there some reason they can't just avoid each other? – Kat
The reason is that Alice and her daughter (my cousin's wife, code name Jane) live close to each other and Alice & Jane keep dropping in at each other's houses, which is a good thing, except it brings about frequent meetings between Aunt and Alice. Moreover Indians tend to see their son's mother-in-law as a significant relation and there's apparently much covert criticism of Alice by Aunt (and some comments in the opposite direction) that puts my cousin on high alert.
Jane is luckily the calmest person and ignores all the nonsense. But my cousin is tearing his hair out because he has to get through 5 months before Aunt's visa expires, and Uncle her husband is so abstract as to be useless in this inter-cultural crisis. He has been busy visiting his own Indian friends now living in the USA while Alice and my aunt trade veiled insults and embroil my cousin and his wife in serial controversies.
I don't know or blame Alice in any way but my aunt can be a quite unreasonable person. I think she is upset to have zero 'Indian style authority' over her American daughter-in-law nor any customary Indian superiority often enjoyed by being the groom's parent. I am sorry to say that my aunt is showing no initiative to resolve the misunderstanding.
So I need help again from the Interpersonal experts: how to help my cousin resolve his mother's problem with Alice and bring Aunt into harmony with her in-laws?