Part time work and esa

I need some advice regarding working while claiming esa with lcwra. 
My husband is physically and cognitively disabled and I am his main carer. He has 10 hours with direct payments but so far his attempts at employing a pa have been disastrous. That's a long story but I won't bore you with it here. 
We have two adult children living at home, both disabled. They are both autistic and adhd, have terrible anxiety but are otherwise fit and healthy. Neither of them go anywhere alone unless absolutely necessary. 
My husband enjoys it when one of them goes out with him into town or the nearest city - they love looking round the shops with him and they help each other on the bus. They are all pretty much caring for each other when they are out. 
My husband has asked if he would be allowed to employ one of them as his pa as they understand his speech problems and are physically able to keep up with him (a problem we've had with pa's in the past). 
I've never heard of this being done before but oddly someone who was dealing with my  husband's sight loss a few years ago asked if there was anyone in the family who could help him. 
If one of them was allowed to be his pa, would that affect their own esa? They have lcwra because they can't go out alone but they are comfortable with their father. 
It seems counter-intuitive for someone who needs help getting out and about getting paid to help someone else who has similar problems but is allowed? It would save a huge headache of finding and hiring a pa and would help one of the kids with their confidence and anxiety, I'm sure.