@Annb, I can sympathise with your DIL. Mine is the same but her's is physio, acupuncture and sports injuries. She still has rent to pay for her clinic premises and it's cost her a small fortune for PPE, sterilisers and meeting covid requirements for the short time she was permitted to open in the last 15 months. She's gradually building the client base up again.
Many years ago my brother ran a small engineering business and thought everything was going well when he won a contract with a large firm. Unfortunately, he then had to have heart surgery and while he was recovering, the big firm decided not to pay their bill. He demanded payment, of course, but they simply told him to sue them for it, knowing that a court case would cost more than his business could afford. After a struggle (with other misfortunes adding to the problems), he was made bankrupt. I'm pretty sure that some legislation was passed, not too many years ago, to stop that sort of thing happening, but it seems still that those with some kind of power (financially sound v new business) still get away with it.
Not a good idea to have too many eggs in one basket, as I have been pointing out to DIL.
Of course, due to the covid thing, life has been very hard for most businesses with extra expenses and less opportunity to earn. I hope your DIL manages to get through this hard time and that things will pick up for her.
