The situation that you just described would be a pleasant improvement for many of the private sector sole proprietors and small business owners that I know.

Her situation sounds actually far more stable and easier than theirs in a variety of ways. Her client is likely quite well-established, and the risk of it "going out of business" or running into insurmountable funding issues is small. Her client will likely be feeding her a steady supply of work, without interruption, effectively forever. It doesn't sound like she has any marketing, advertising, or customer-acquisition overhead. She doesn't have the overhead of negotiating a contract and fees with each client. Her working conditions are likely quite safe and comfortable (as compared to those in the trades, for example).

I don't think she has much to complain about when compared to what those in the private sector have to deal with.