My MIL worked sporadically and part-time. Has been assessed with arthritis in her spine (but she is just as fit and able, prob more so, than my mum). She’s younger, has overhauled her garden, moved paving slabs and last week wallpapered her lounge. She has a sympathetic doctor who has classified her as disabled and she gets:
She won't get PIP because her GP has "classified her as disabled", it simply doesn't work like that. She will have had to fill in the PIP form (which is a huge form and take ages) and will have had to provide evidence for each of the questions she has answered. For example, if she has said that she struggles to cook a meal due to her disability, she has to have detailed those struggles, then said what help she needs, who provides it, what aids/adaptations she uses, and what happens if she does not have that help/those aids, she then also needs to provide evidence if this via diagnostic reports, assessment reports, letters from doctors, etc.
2 bedroom bungalow and various bills paid for
Bungalows via social housing have eligibility criteria, if she has one then she meets the criteria. Not sure which bills she has paid for as PIP does not qualify you for free bills
Motability car - a gold coloured Renault Megane convertible with electric roof at one point, plus tax and, I think, insurance paid for. Replaced every 3 years.
Meaning she qualifies for higher mobility rate of PIP. This is not a "free car", she forfeits the mobility portion of her PIP to pay for it, my aunt gets a mobility car and gives up £68 a week from her PIP for it. Disabled people need a reliable car that is not likely to break down, often the car needs to be adapted (e.g., wheelchair space) and these cannot be done to older models. The car is on lease, it is not theirs to keep.
Blue badge for parking.
Again, this means she meets the eligibility criteria. They are not easy to get and applications have to be evidenced.
Free glasses (costing hundreds of pounds per year)
Once again, she obviously meets the criteria. I get free eye tests and I'm not on benefits but I have a first degree relative with glaucoma.
Multitude of benefits, I am not kidding, she is rolling in it.
Mmmhmmm 
Treated herself to a £2,000 puppy last year.
Its up to her what she spends her money on.
My mum has to save for when she needs new glasses.
Maybe your mum should look into claiming PIP.
Do you know the difference? My MIL knows how to play the system. She just moans and tells sob stories until she’s given what she wants.
Moaning and sob stories do not qualify someone for disability benefits, as detailed above.