Is my DD being rude or is this just a part of her autism?

[slavetolife]

My DD is 17 and on occasion when she is upset with someone (mostly me, or her auntie), she will bombard with long text messages which I can only describe as like a stream of consciousness - obviously this seems incredibly rude when she does it, however I have learned that the best thing to do is to ignore it and wait for her to calm down - my sister however bites back and makes the situation worse.

Is this a "thing" with some autistic people? I'm struggling to manage the relationship with my siblings and DD as they just don't get it - I hardly do myself, she was only diagnosed 18 months ago! Generally my DD is quite well mannered except when this happens but it's almost like she is having some sort of meltdown at that moment.

I'm a tad confused, so when she is upset with a person, she sends that person a long stream of conciousnessy text?
I wouldn't say it was rude, I'm autistic and do a very similar thing. It may be rambly because some people with autism struggle to articulate their own emotions, so she's more or less saying whatever is in her head at the time.
The text is probably because there's a layer of separation from her and whoever she's talking to. It can be incredibly stressful to speak to somebody face to face if you're angry. I remember once I had an argument with my mum, amd I had run out of tampond. Despite the fact that we were both awake I had to taxt her to ask her for some, because I just couldn't talk to her.
I think you're being a little OTT describing it as "incredibly rude", I don't think it is, but assuming that it is a very rude thing to do, she probably doesn't mean it. It's probably a combination of being upset and needing to vent, and also from her perspective it's probably no different to you complaining about work or a family member when you get home.