AIBU for sending my mum home early?

Get the ticket she has swopped , and get her out of there. If you were paying for the travel book it and never offer to pay for her to visit again.

She’s been with you for a month!! You have the patience of a saint. Send her home. Save your emotional energy for your children.

Wow your better than me I'd have thrown her out the house at 1am

Has she got a drink problem?

Take my comment with a pinch of salt op, but she raised you ok didn’t she?

Hi OP. It is perfectly acceptable to have boundaries with your mum. You don’t have to accept any of this behaviour. It’s not your job to manage or fix your mum’s behaviour, it’s entirely her own responsibility, trauma or not. She is an adult, and if she wants to maintain an adult loving relationship that’s up to her. That’s her job. You don’t need to carry any guilt. And now you have your own children it is your job to model what having a constructive relationship looks like. Do it for your children. Not saying cut her out of your life but accept no challenges to your parenting. She’s had her chance and now it’s yours. Just because she says “x, y, z,” doesn’t make it true. She’s entitled to any opinion she likes, but that doesn’t give her the right to air it in front of your child. You can do it, if you love your kids they deserve positive role models and currently she isn’t one. That may or may not change in the future but get through the next day or so and consider writing it all down to give her to read on the flight home. She doesn’t have to like it, but you are not obliged to have this shit in your life with a newborn baby and health issues. Use that energy to recover and recharge once she’s gone, set boundaries and don’t look back. Best of luck.

If she had a ticket for next a Wednesday I would let her stay but I would be clear - no alcohol at all. Be civil and polite but keep it simple. You know your mum so don’t ask her questions which might provoke a discussion in any way and don’t discuss anything with DH in front of her. Don’t discuss what you are going to do about her future visits, you will need to think about it any way.
A month is too much for a parent with such personality. I would say 2 weeks max once a year if it’s absolutely unavoidable.
By the way is it her personality or there is cultural difference in how she sees parenting? If it’s cultural it’s trickier she would struggle to see your point of view.
Also do you have siblings and if yes do they have the same problem with her? I’ve found that if my sibling and I are both saying the same thing to our mum she listens more.
However drinking episode was unforgivable. I wouldn’t want her staying at all unless she would work out herself how wrong it was and specifically apologise for this. Is it a regular thing for her or out of the character?

and yes to @NerrSnerr approach

My mum is an alcoholic and really, really tricky. She is even now she doesn’t drink. I find visiting her much easier than having her at mine. We have a number of activities I can take my children to when she’s being tricky (Aquarium, swimming, parks etc). We visit for 3-4 days but book ourselves up so we only have short stints with her. It’s the only way to manage it.

How is she getting ahold of alcohol? Hide it remove it pour it out

I wouldn’t tell her she is not invited back until she leaves the country and is in her own home. You don’t want her kicking off and refusing to leave.

Mm. Getting blackout drunk is not everybody else. 🤨

I’m sorry to hear about her upbringing, but she has had decades to do something about it. And she used to have money? Could have paid for a therapist. If she didn’t have money, there are books, resources that would have been better than making her daughter feel like this.

Unless your mum has cognitive issues she should have some self awareness. She had her time being a mum and she needs to learn when to shut the fuck up. Especially if you've just had a baby. And any idiot can win a child's favours giving them rubbish to eat, that doesn't make her grandmother of the year. Good for you knowing when you've had enough. And a month would be a long time for anyone, even if they're super helpful having someone in your space is hard. She's broken up a marriage before, that's crazy. You should tell her how you feel, guilt is natural. You don't need to be unkind about it. Tell her you love her and want to have a relationship with her and that's why you are telling her. She should be helping and respecting your rules not undermining you. I'm speaking as an overly helpful person whose learnt, trying to learn when to be quiet. She can change, she can do it, but you need to tell her, write a letter maybe, and yes get her on that plane. Go easy on yourself, emotions all over the place, sleep disruption and a body that doesn't always feel quite like yours. Factor in your thyroid and you've got an older child, and chuck in an overly helpful mother and most people couldn't cope with that.

“Around 1am she woke me up shouting and swearing about me.”

She WOKE UP the mother of a three month old baby??? I am just astounded. Does she have no care for the baby? And she has been with you for a month - I think you’re up for a sainthood, OP. Do you sleep with DH and baby? I think my own DH would have had a few choice words to say if his MIL had woken him up in the night shouting and swearing. OP, that is so far beyond acceptable, words fail me.
Next time she comes, if you’re in control of buying the tickets, make it no longer than a week. I just can’t believe that a mother would be so unkind to her DD. The idea of waking my own beloved DD when she is tired and hormonal with a tiny baby - well, it’s unthinkable. As for telling your six year old that his future wife will turn him against you - I’d have been getting her coat at that point. Your DC: your rules. As a DGM, you can give gentle advice to your DC, but not in front of the DGC, and you most definitely don’t ever cast aspersions on her or her parenting. What on earth does your DH make of it all? It would be quite a while before I would be thinking of inviting her again.

If that happens, come back to this thread to remind yourself how awful her behaviour was x

If she’s been here a month, her flight is booked for Wednesday, she has no money and you’d have to pay loads to buy a new one, then I’d just wait till Wednesday.

She can be very amusing..
But her current behaviour is very far from it.

You don't want someone bursting into your bedroom drunk in the night and swearing and shouting at you ...
point out to her that is a sure sign she's probably had a long enough visit and should go home as its clearly not doing her any good.

I'd find all the comments insufferable after a while, there's only so long you can keep turning a blind eye, particularly if its making it harder for your to manage your six year old.

@Looneytunez try and put this behind you but learn from it. Let her stay for the rest of this holiday and be as nice as pie so you are not left feeling guilty in anyway once she heads home. You’ll know who was exactly in the wrong.

However, this isn’t going to change. Every visit will be the same. So, keep in touch by phone. When you fancy seeing her, you and your family go to her. You can choose a hotel nearby or decide to stay with her for the chosen length you can handle. It’s probably best she no longer comes to you, it isn’t good for your kids to have a toxic person staying and for too long. Keep your visits to her brief so that your kids see the nice side of their grandma only.

A month is more than most people can manage and that’s without the getting drunk and swearing.