hello, Rae. After a period of three years, they are now the responsibility of the family concerned 
- this sort of scenario is why it is always a good idea to organise an adoption through a rescue/charity who can provide lifelong back up if this sort of thing happens.
Your friend has a number of options. Presumably these dogs are now quite elderly? She could try the Cinnamon Trust, or the Oldies Club who as name suggests specialise in older dogs. She could also try a local all breed rescue - whereabouts roughly in the UK is she ? We could make some suggestions.
The main thing is to avoid the RSPCA, your dog pound/dogs home (they will only have seven days, if that before being PTS) and under no circs should she advertise them on Facebook, Gumtree etc as they could end up in all sorts of horrible situations.
Also, realise you may have tried this, have the dogs been properly assessed by a vet? Is the incontinence something which is going to be lifelong or is it just a temporary problem? Many continence problems can be helped/minimised with vets help and medication.
Also, any charity that does take the dogs will want to know:- full health history, list of vaccinations, description of character, whether the dogs should be a pair or can be separated, whether already chipped or neutered. It's useful to know this so your friends can gather together all the relevant paperwork, including anything to show the original transfer of ownership.
Hope this helps.