How to you ‘thaw’ prickly people?

She has had a few shitty life events and is understandably prickly. I wouldn't talk to her about it - it won't solve anything in practical terms. And it won't help emotionally either because it's clear she doesn't want to talk about it.

Its not you its her having a hard time. Try badge supportive and it will pass.
Take her out for a walk (and chat!) or go out for a few drinks (and chat)? X

My sister used to be like this. I found I could only really talk about tv programmes and books with her for a while - steer clear of news and other people (anyone at all). Absolutely anything that could in any way be construed as an attack on her or her values was construed as exactly that. She was such hard work. Thankfully she has now moved past that stage and is genuinely good company.

2 years ago isn't recent. Maybe she is moving on but you always take her back to the past?
I wouldn't be amused if my sister kept bringing up a bad time and heart break for me from 2 years ago. Can you try talk about common ground, I don't know Xmas plans? A Christmassy day/night out and not bring up losing her flat and relationship 2 years ago?

Exactly. The worst thing you can do is bombard her with concern or creep around trying to get her to like you. Back off, be civil and unemotional, get on with your life, and stop trying to get her to do what you think she should do. Not having an agenda is much the best plan.

In my non expert opinion...

You think she needs a heart to heart and some advice from you.

She knows you think that and that is the last thing she wants. Prickles are her barriers.

Accept her as an equal, trust her, stop pitying or judging her.

If it's someone I care about and want to maintain a relationship with, I let their bad behaviour go if they're going through a tough time.

I just ignore it and pretend it's not happening. I don't bring it up with them or try to talk about it, unless they want to.

This.

You try to make them feel better about themselves. So avoid any messaging that there's a problem (no sympathy unless it's clearly sought, no advice, no criticism) seek out things to praise about them and positives about their lives. Be subtle though as you don't want to patronise. Ask her opinion, ask her advice where relevant to shift the dynamic aware from successful sister/unsuccessful sister. Be cheerful and positive. But have your boundaries in mind, you are not there to be rude to or to be an emotional punch bag, so know when to walk away from bad behaviour.

It sounds like you are trying to force something that she’s not ready for. She clearly wants to deal with this on her own terms. Let her manage it he way.

You seem to be imposing your approach on her without stopping to think about whether it’s right for her. Back off a bit and give her some space. She will come when she’s ready.

My sister is like this at the moment. Whatever I do I can’t get it right so I’m just leaving her to it now.

I think just don't bring up any of the heavy stuff unless she does. You could try inviting her to go for a drink/shopping/something else she likes. If she doesn't want to, then let her know the offer still stands in the future if she changes her mind.

I’d much rather my sister suggested an activity together, was good company and made me laugh and relax than have an intense heart to heart about things I was struggling with. Just spend time doing something joyful. She needs you to like being with her cor who she is not how you think she ought to be. It sounds as if you really care about her OP so I hope you can find a good way forward. Sisterhood can be a very special bond.

What does she like to do? Can you start going to a yoga class together, watching a tv series together, going shopping meeting up for a coffee?

I think you need to build trust and positive experiences before you attempt a heart to heart conversation.

Leave her alone.
Give her space and time and grace to rest, recuperate and heal herself.

For whatever reason that heart to heart connection isn't there with you right now.
Maybe it was and now it isn't.
Maybe it will be again one day, maybe it won't.

Stop trying to force the connection, as it is right now, to be what you hope it to be.

Concentrate on what does work and what you've got.

Is the best way you connect together right now very low key things? Such at you offer her to lend her a brolly when it's raining, she says ta... And that's it. Nothing dramatic but small exchanges that are tension free...

Or maybe there's something a bit more meaty that works.... You both enjoy a programme and can watch it together without being annoyed the other person is there. Maybe even have a small conversation about it...

Basically whatever interaction you can have with her, that isn't a 'planned chat', but is spontaneous and works ok, no drama or tension for you both, is what you need to allow space for, no strings attached.

If you honour those real moments she will appreciate that positive relationship, even if it's small fry in the grand scheme if things and it will allow for the potential for it to grow into more in the future.

Keep pushing for something that's not there right now. Or pounce when the going is good to grab that conversation you're going for, so any relaxed moment is paid the price for in owing a chat... And you'll create distance.

Lovey , she probably hates everyone including herself at the moment. Some good advice on here. Do you share any interests ? x

I agree with some of the previous posters.
Just spend quality time with your sister. Do something fun.

Perhaps she will suddenly open up, and talk. Or not.
But she will know that you want to spend time with her.

To be fair op it’s a lot to go through, you need to relax yourself and just let her get there. Maybe try and have some nice times or something

Treat her to a night in the cinema. Afterwards talk about the film.
If she doesn’t ask for help or advice don’t give it but you can support her in other ways.

I know it’s cause she’s unhappy with her situation, but she REFUSES to talk about it. “Having a heart to heart” isn't really an option sadly, even though it’s what she needs, she will not allow herself to be vulnerable.

She doesn't have to be vulnerable, she doesn't have to have heart-to-hearts and she doesn't have to talk about her situation if she doesn't want to. It sounds like you're fixated on the idea that talking it through and finding solutions will be beneficial to her. Maybe it would work for you but her prickliness is telling you she doesn't think it would work for her. Maybe she'd rather you take her mind off things by talking about something light-hearted or frivolous. Maybe she wants to focus on her interests or hobbies and not her health or lovelife or job. Maybe she's prickly because you insist on bringing the conversation round to the heavy stuff that depresses her.

She's not ready to talk to you, and you've framed that as her not liking you any more.
Are you absolutely sure that her talking to you has never backfired on her in the past?

I can be a self confessed prickly person when people give me a reason to be / I want to be left to it. Especially when people go offering solutions to what they perceive to be ‘issues’ when they’re not wanted, nor needed.

My advice is do the opposite of whatever you’re doing. It’s not on you to decide she needs to open up and be vulnerable. Take her at face value and have simple, un emotional exchanges and the worse that will happen is that she’ll become safe in the space and will round off the prickly edges whilst maintaining a degree of separation.

Best case scenario the walls will come down a bit and she might let you in as you’ll become a non confrontational, safe space.

If I’m prickly, I just want left to my own devices and people to keep their noses out my business.