Can you get NI stamps from ESA, PIP, the USA or anything else?

Sulaco86

My wife used to be self employed as a Dog Walker, but had to quit her business about four years ago for health reasons. She has had CFS for over ten years, and it became impossible for her to continue working at that point. She has since been diagnosed with MS as well, so a return to work is unlikely. 

Prior to stopping, she always paid her NI stamp, and when I checked on the government portal a few months ago she was only short a single stamp, the most recent, with 20 years paid before that. She is a US citizen who has lived here for 24 years, so she only started paying NI relatively late. She has 20 years, and is 53, so she can't really afford to miss any to get her full pension.

Would she be eligable for any benefits which would pay her NI stamp now she is unable to work? I've read that ESA can, but it is dependent on the previous two years of stamps being paid, which by the time we could get an application in she would probably be missing both of. Can it be back dated to when she stopped working? Alternatively, if I paid her last two stamps would she be eligable then, or am I just barking up the wrong tree? I get the feeling ESA is intended for gaps in employment rather than being permanently unable to work.

I know she can probably apply for PIP, but I don't think that pays the NI stamp.

I am a higher rate tax payer, so we likely aren't entitled to any means tested benefits, and that's fair enough. But I know there are some benefits where even if you don't qualify for any money, just being eligable can give you an NI stamp. Child support for example (our kids are grown up now). Is there anything like that she could get?

As another possibility, I have heard that there is a reciprocal arrangement with the US social security and the UK. Many years ago my Mum worked in the US for a couple of years and by paying US social security she was able to get an NI stamp to cover that gap. Is there any way my wife could use that to get NI stamps based on the years she paid into US social security before she moved here? She is now permanently living in the UK so she won't return and ever need those in the US. 

Failing all that, is the only way forward we have to just pay the stamp each year? With her likely needing 15 odd years to qualify, that would be quite a bit of money.

Spoonie_Turtle

She can claim ESA on a credits-only basis (technically, claiming NI credits on the grounds of having limited capability for work).  I believe she would still have to have an assessment in order to qualify for having her NI credits paid for longer than a year. 
The longest that can be backdated is 3 months. 
She'd need to have a fit note (sick note) from her GP as initial medical evidence within 7 days of applying.