Then the issue is she needs to reclaim PIP. It takes a while to go through the process, months sometimes, so she's going to have to strictly budget for now. If she won't get rid of the dog (understandable, it could be her only reason for living at this point) then she needs to prioritise food for herself and the dog and cut absolutely everything else, including heating, insurances etc. she may well also need to go into debt until her PIP claim is approved and her back pay comes through, which she can then use to pay off her debts.
Her local council might help, in my area they have a support team that is separate to social services and they can provide tenancy support (it's fine if she's a home owner too, it's for helping people like her deal with the basics of life and get back on their feet).
It's unrealistic to expect people to fetch and carry for her, unless she's organising a supermarket delivery or has a charity willing to collect food then she'll need to get herself into a position to take a taxi to the pantry etc if public transport isn't an option, even if that's a credit card for now.
The PIP process is also really really shit to go through so if she's able to survive on others help she may not be desperate enough to claim it, as horrible as that sounds if you want to protect your own time and energy you may have to get tough with her.
She may also need to look at moving somewhere else cheaper, if she's living somewhere that's too big or too difficult/tiring to navigate regularly with her disability. Downsizing If she's a homeowner. If she's in social housing she needs to contact them because they may have a budgeting team who could help. If she's private renting she needs to accept food is more important at this moment than becoming homeless, which can't happen overnight anyway, it takes months to evict someone.
She sounds like she just has no clue where to go for help at the moment and has left it too late until she's actually run out of money before asking for help