how do I handle a dog with very high anxiety who won't eat or dink or go potty ??

I have a dog who si supposed ot be coming over thanksgiving for about 8-10 days The dog has been here 3 times now a meet and greet , a day of daycare in which I had to call the owner to come and get her b/c I had been sitting on the cold wet ground for 4 hours off and on trying to get her to come to me ,and a visit for about an hour in which the family stayed here with her. I have been told by the family she sin't bonding with anyone in the family she is hardly eating drinking or going potty, All she does is pace and pant and they said she does that at home also. It is like having a feral dog . I'm not sure I will be able to handle a dog like that. They are bringing her for a short visit on Friday but I don't think she is going to be any better then teh last 3 times. I do everything I can when I ahve a dog board. I never leave them unattended outside I also make sure I know where they are inside. I do everythign I can to make sure tehy are safe and comfortable and teh owners get updates several times a day with pictures. This dog is different tho I worry that the way it is she will find a way to jump the fence as I know adrenal will take over and will make you do things you would normally never do. If this dog were to get loose despite everything i do it will run and not look back at all. Do I tell the family I don't think it will work out even tho they already booked the stay or do I take a chance and see if it works out I do have a plan in place for the dog if/when it comes but even the best laid plans don't always work. The family did rescue teh dog and has only had it about a month and a half at most .