So I don't think you're being unreasonable for it to have crossed your mind, but hopefully from all the PP comments you'll have worked out that it's obviously not for you.
Some great advice above, and what I would suggest might be covered by one of the links, but in case...
Have you tried a skills based CV? This won't work for formal applications, but if you go back through your previous jobs, draw out all your skills, and then I would group them such as:
Administration
Communication
IT
Management
Interpersonal
Financial
(Whatever works and matches with your desired job).
Then think hard about all the skills you have gained and demonstrate through being a mum, household manager, managing your disability etc
- eg multitasking, managing a busy diary, liaising with various organisations, conflict resolution, mediation, budgeting, demonstrating active listening skills etc etc - and slot these into your skills lists..
I even used planning my wedding, project management, managing building contractors etc for my CV before.
You take up the first page with these types of bullet pointed groups, with short examples for each.
Ideally have a lovely personal statement up top, so they get a great initial overview of who you are as a person, what you can offer, and what kind of role you are looking to fulfil.
Then your skills
Then a list of your relevant qualifications.
Then lastly your experience, in a short bullet pointed list.
Call yourself something like Household Manager or Primary Carer of young people for your gap. It is a job, it just happens to be an often thankless and unpaid one!
I used to be an employment advisor and in this way I got people interviews and jobs; people who had never ever worked, who had been carers all their lives, or had significant disabilities.
It is all about how you market yourself. Ultimately an employer wants someone who can do the job well and be part of a team. Show that you know how the corporate world works, you know about meeting deadlines, being a self-starter, using your own initiative to problem solve, communicating at all levels and who wouldn't want to employ you!
I would do this exercise just to give your self esteem a massive boost, everyone I've worked with has come away feeling a few feet taller, and like yeah world, I have got shed loads to offer actually! You'd be lucky to have me!
And, at the same time, find out about some free courses, do some freelance work on the sites suggested above, it's easy to set up as a sole-trader and get some things onto your CV.
Also ask your job centre if they can refer you to an employment coach (often a privately contracted company) and for further training. And then you will have courses to put down for your recent activity, and a coach to phone their contacts and make introductions. They will likely have targets to hit and be very motivated to help you find work that suits and is sustainable. We were measured on entry into work and 3/6 month sustained employment.
You've got this! X