Who's in the wrong here?

I understand you are tired but you are an adult and you need to prioritise your sleep.

If you don’t prioritise your sleep and cop on to yourself, you won’t be able to care for anyone.

You're knackered, she has overreacted. I don't think you were being unreasonable but this probably needs to be the impetus to cry as loudly as you can for help with your caring responsibilities.

That might be to your sibling if it's your parents, or even if it's not it might be to them to help you try and get support from the council, it might be the council, or if it's a young baby it might be someone else. Sometimes something has to happen to highlight that all our reserves have been consumed and we need to change how life is. To be clear, this would have pissed me right off as well and I don't have significant caring responsibilities, but it also sounds like you're exhausted and totally maxed out. No one shouldn't be sleeping for 48 hours.

This was a guest
so not her door key

Outside of Mumsnet I have never heard of people going out for the night without their door keys.

So actually none of your tiredness is down to her?

There are things here that are outside of your niece's control. The fact that you had already stayed up for 48 hours but still offered to stay up and wait for her to come home wasn't here fault. Also, that you had to do your caring job until 12.30am that night is not her fault. Yes, she came home later than she thought she would and that is annoying, but most of the tiredness is caused by things that she had nothing to do with.

Because as I put if I was usually still up there is no need.

If she thought she might be out later then I think she should have said & asked for a key.

I think if you're staying with someone it's generally good manners to stick to doing what you said you would.

Hmm having read all your posts it does rather sound like your niece might be taking advantage of your hospitality a little. Is she staying over because your house is handy for nights out in a city compared to her actual home? And you have caring responsibilities that include doing caring activities at all hours of the day and night? Elderly parents? Or a disabled spouse or child? No matter. It might be worth a chat with your sibling who is her parent to smooth things over. I doubt things are irreparable but she likely has no idea how exhausting your life is and is not helping with coming back to your house at all hours. Also her own key would be handy if she's regularly stopping over.

Why not? This way if she decides to stay out later or you decide you want to go to bed earlier, which you might if you're badly sleep deprived, it's no problem.

This.

OP I think its also stressing you out that you have fallen out.
Forgive each other - send a text
You'll probably find she's more than ready to apologies, she said she'd leave to give you some space.

It sounds like you need to steal your sleep when you can. I'm sure you explain that, she will understand.

FYI my lot are always forgetting keys. We bought a key stone and put it in the garden for them. (amazon £5is) and go to bed. But if for any reason they couldn't get in, they'd just ring me. I'd stumble down and let them in and stumble back to bed.

She's totally out of order. She's 20 and it's her responsibility to either take a house key or to get home before you go to bed. It's not fair that she expects someone who's exhausted anyway to wait up until 1.30 a.m. She's being incredibly immature when she cries and leaves - she should be giving a heartfelt apology and asking what she could do to help you.

If I was usually up until 11 & it was just one night I probably wouldn't have given a spare key either.

Ok so I’d guess that last night something happened that has upset her and made her very emotional

Why exactly didn't she take a key?

You said it here:

I couldn't have slept.

You're obviously running on empty but she wasn't really the cause of that. She had one late night. It wasn't that one late night that left you in a state. It was the fact that you'd previously been up for 48 hours, then only had four hours' sleep, then couldn't sleep in after her late night because you have caring responsibilities.

Essentially, you understandably lost the plot through sheer tiredness, but it really wasn't her that got you to that point of exhaustion. It's everything else about your life. And you took it out on her and had what sounds like a massive meltdown in front of her.

I have lived for extended periods with virtually no sleep and a very stressful living situation. It's very hard and it messes with your head and it genuinely does affect your entire perception of what's happening, as well as affecting your behaviour. One late night doesn't do that, but a long period of severe deprivation does and I suspect your reaction was far more alarming than you think it was.

She should have been more considerate but she doesn't know what's going on in your head or what your personal stress and exhaustion feels like, and you chose to wait up instead of leaving her a key.

You CHOSE to sit up waiting for her, rather than just going to bed and getting an early night. That is the unhinged part of your story. And then when plans changed, you stayed up, fizzing mad, rather than hiding a key and telling her to let herself in quietly.

She has a lot of growing up to do. Perhaps it's best she's gone for a while, at least until you can give yourself some much needed TLC. Hope been to the docs and explained how you feel too, see if any help to be had.

Don't sweat her, she behaved a little dramatic.

Edit. Sorry, didn't realise she only stays on occasion.

Adding to the chorus of she's 20 - give her a key. I have a 20 year old and a 18 year old and when they are out I just go to bed and see them in the morning. I don't wait up. They know to ring if there is any issue and there never has been.

The "I couldn't possibly sleep" is martyr behaviour. This is a choice. She is 20 and doesn't understand whatever caring responsibilities are keeping you up half the night. She thinks you are being crazy and overbearing. You think she is being rude and selfish.

U are both in the wrong. Her for giving times and not sticking to them. And you for staying up for 20 year old. It’s not her fault you’re exhausted. She’s a grown adult. But she’s allowed a life without u hanging about waiting on her. Living together won’t work if you are not honest with each others expectations.

OP, she's 20. Give her a key and trust her. If she was at university nobody would be waiting up for her. You can't limit her life because you can't sleep until she's home. She isn't responsible for you, no matter what you have done for her in the past.

You sound like you need sleep and your own space. I am sorry life is difficult for you currently. Perhaps niece is best housed elsewhere until you are on a more even keel. I don't think she has done anything wrong. She's 20 and should be able to have a night out without feeling guilty. I think maybe you are in a place where you can't be thinking about others and just need to focus on your own needs, which is fine. Hope things improve for you.

You sound like Joan of Arc..