Can I get advice on UC rules...giving up job due to health?

[SomeNameAvailable]

My friend has been a carer for many years. She had health problems before but still managed to work. She caught Covid and now has long Covid, her health deteriorated and she was signed off work for at least 12 weeks.
She loves her job but realistically doesn't think she'll be able to cope with it anymore and wants to look for something less physically demanding when she's well enough to go back to work.
She has made a claim for UC to help but is worried that if she hands her notice in she'll be sanctioned. Citizens advice have told her to claim esa, and that she can put in a claim 3 months before her sick pay is due to end. She doesn't know what to do, nothing is clear. UC have messed up her claim and paid her short, she's now in rent arrears and receiving eviction letters despite explaing her situation to the council (her landlord).
I'm so angry for her, she doesn't need this stress on top of illness. Is this the thanks our carers get for everything they sacrificed last year? The threat of losing their home?!! What advice can I give to help her? I know nothing about how UC works. I'm bloody disgusted she's going through this.

Keep handing sick notes in eventually UC will send her for health assessment and possibly put her in non work related group. If she quits, yes she will be sanctioned, the rules are the same for everyone.

She can claim New style ESA ( assuming she has paid NI contributions over the past 2-3 years) but would also need to claim Uc for help with her rent. the New style ESA is deducted pound for pound from the UC. If she is private renting, it may not be that Uc have messed up, but more that the rent element they will pay does not fully cover her rent as the rent element is based on the local housing allowance for her area.
Is she still receiving SSP currently ?
As above she needs to keep handing in sick notes. On day 29 of handing in sick notes she should be referred for a work capability assessment and will be sent a Uc50 form to complete. then she will be assessed but these assessment are currently taking months, there is a backlog. Only if awarded LCWRA ( Limited capability for work and work related activity ) would she be granted extra money on the UC claim. She should not hand her notice in, she should exhaust all sick pay. If she hands her notice in they could still ask her to apply for jobs etc until she has been assessed although her work coach can apply some dsicretion as to what they expect of her.

I would also advise that she applies for Discretionary Housing payment through her local council - this can be awarded to help with arrears and to help with the shortfall in rent payments if her Uc rent element does not cover her full rent.
Has she also applied for Council tax support?

Sorry I should also add - she cannot claim the new style ESA until SSP is coming to an end, and as previously mentioned she will be no better off by claiming it if she's already claiming UC unless the NS ESA works out more than the UC ( unlikley if she is getting help with rent). However claiming Ns ESA does have benefits in that it is a non means tested benefit, so for example if she met a partner who had earnings or savings that meant they were no longer entitled to UC, then she would still get the Ns ESA as it is not means tested.

If she has difficulties with her daily living activities and/ or mobility she can also consider claiming PIP if she has had difficulties for more than 3 months and they are expected to last another nine months.