What is my sister in law entitled to now?

Oh, you may well be right.
Its all so complex, its really best to check out with people who know.

I’m not sure that’s true*Miss*.one type of JSA is NI contribution based to start with - I think what would matter would be any money she got that was in lieu of salary eg 3 months notice. would mean no JSA for those 3 months. Off to the Citizens Advicd with her -do NOT get advice from Job Centre first

Yes it does.
She would be expected to live on that money until she goes below the threshold, kitty.

She got a good sum when she's made redundant, does that count in her savings?

www.entitledto.co.uk/
This link is to a benefits calculator. You just fill in your circumstances, and it will work out your entitlements.

Or maybe Citizens

www.gov.uk/jobseekers-allowance/what-type-you-get

This is a starting point followed by good old Cotizens Advice

If she is still considered to be of working age, and provided her savings are less than 6 thousand, (I think) then she will get jobseekers allowance which is around 73 pounds a week.
Help with council tax bills, too.