No it doesn't work like that. Carrying out your duty as executor incurs certain legal responsibilities.
As it sounds as if the estate was quite considerable (house to sell) and the laws of probate kicked in. What part did the solicitor play? Joint executor perhaps?
After funeral expenses have been paid off, the next duty of the executor is to realise any assetts and pay off debts. There was a house to sell. And debts to pay, even if just council tax, utilities, estate agents feed, etc. and anything expended on behalf of the estate. This could include the cost of hiring cleaners and people to empty the house. Though I don't see why your sister couldn't put in a claim for this if she did it herself.
Account need to be kept showing all assetts and all debts and only after that is the remaining estate allowed to be divided up according to the terms of the will. So that's why the charities, as beneficiaries, are entitled to see the final spread sheet. As is/was your sister.