Was I right to stop Dd1 waking up dd2?

[Wibble1999]

Dd1 (25) live away from home, dd2 (18) still live here. Last night dd2 got so drunk that couldn't go to work and will now be sacked as was on final warning for same thing.
Dd1 did the same thing at 18...... So been there got the t-shirt.
Well dd1 came round this morning to wake up dd2 and read her the riot act (no irony there!!) (and I suspect laugh at the fact she has no job)
I refused to let this happen.
Mainly because I knew the fall out would be dd2 in such a rotten mood that I would be forced to leave the house for the rest of the day to avoid a full scale arguing match.... Right now I just will not be able to keep calm and don't need a half drunk verbal abusive rant.
Dd1 was so mad at me ...shouting, to the point I asked her to leave.
Was so tempered to say hand back your key, so she can't just walk in the house like that again.

Your older dd needs to learn to mind her own business. Your younger dd is an adult who has made a stupid decision and will be paying the price. You have the right to have as much peace as can be managed in your own house.

have a

Yes you were right. Your older DD is now living away from home so she doesn't need a key and she should not becoming round to shout at her sister it is none of her business.

Dd1 came around again and again I had to evict her. This time it was clear it was to gloat.
Dd2 is annoyingly unrepentant to her actions and is out drinking again.
Tell me they grow up....pass me the teapot.

What's the back story with DD1? Has she always been so nasty?

They do grow up eventually. DD2 was very difficult between 18 and 19, However she then went to uni. She is now 24 and a mature young lady. Well mostly anyway

How did DD1 get wind of all of this?

If you told her what DD2 had done then maybe don't fill her in again when something happens?

How much does DD2 drink normally? Is this bender unusual?

Dd1 has MH issues so yes this is normal. Her sense of right and wrong are so off I never let her know what is happening.
She was out with dd2 - dd2 had also told her about the disciplinary.
I wouldn't be surprised if dd1 hadn't egged dd2 on to manufacture this situation, she seems to encourage dd2 to make every mistake she has made.
Dd2 is very very believing when it comes to her big sister, will not hear a word against her and every time she is lead astray by her thinks it was just bad luck and not manipulation.
The drinking is once a month on pay day. Unfortunately her friends all do the same, but they don't have work the next day as they are at uni.