@ToothFairyNemesis
The Mail article said £1million over 15 years, I can’t see how that is possible.
If she managed to get the absolute highest rate of everything going, which would be extremely difficult, then it's easily possible on two claims
If she had Incapacity Benefit/ESA, plus the highest levels of DLA and then the additional premiums for the most severly disabled people then you are looking at 20k a year. So 300k x 2 claims right away.
Then you have carers allowances (and any associated benefits claimed there), housing benefits, council tax benefits, free prescriptions, free dental care, free opticians and glasses. Before you even get into adaptations, any home care or the likes.