"I cannot see how anyone can say I was in the wrong when we had the Indian even though DH had to make do with reheated chilli and I was all smiles when they arrived and didn't bring it up."
It sounds as if you behaved perfectly, but you resented it. And it is the resentment that everyone is picking up on.
"But when you look at the bigger picture I think it was."
Now that's different. If the bigger picture is that DIL is someone who always has to pick and quibble until everything is to her convenience, then yes, she is being (probably completely unknowingly) a pain in the arse, and I think you should learn some techniques to deal with that rather than stewing over it and potentially ruining a decent (if not perfect) relationship.
In this case I think you should have stalled and thought about it (you can do this when you get a text) rather than rolling over and getting Indian. As you are clearly pissed off about it (as symbolic of a range of things, I get that)
Here is the generation gap in action: older women (GROSS GENERALISATION ALERT) don't do assertive, therefore don't get what they want, therefore resent younger women who do do assertive, and they seethe.
Suggestion for next time
"that would be a lovely idea for another time when DH can't join us, but as he can't eat it, I think it would be nicer to stick with the Chinese which we would all enjoy, and then it can be a treat for everyone!"
"And when someone has invited you and will be paying I think it's rude. It's not something I would do." no, neither would I. the "who is hosting" thing is a good point. Maybe turn it round and say "oh well we were going to host and get Chinese for everyone, but if you want to make it a joint thing and bring some dishes, then Indian would be fine"
BE ASSERTIVE
Then you will find out if she is a spoilt cow or just "modern"