"PAAE is available to reimburse Members for the additional expenses necessarily incurred in staying overnight away from their main home for the purpose of performing their parliamentary duties."
In other words, the charges must have been wholly and directly necessary in providing accommodation for the MP, not her 'dependent' relatives. And I doubt also that Miller's definition of 'dependent' comes anywhere near the definition of 'dependent' relatives used by the government for immigration purposes;
- Parent must be unable to wash/dress themselves and
- Parent, even with financial and practical help from British child, must be unable to obtain required level of care, because no such care is available and there is no one else in the country who can provide it, or because it is unaffordable and
- Sponsor must have sufficient income / savings to be able to look after their parent without recourse to public funds