I don't know exactly why she gave up the piano, but it may have had something to do with her falling out with Herbert. They were married in 1907, Pat was born in 1908, and they were separated, and basically not-on-speaking-terms by 1911. It was the piano that had brought them together in the first place.
But she spent the rest of her life acquiring skills, and then dropping them. She worked in ceramics (and had a piece exhibited at the Victoria and Albert museum), had a one-woman-show, sold everything, and dropped ceramics. She trained as a bookbinder, became an expert, and dropped it. She did quite a lot with fabric, spinning, dyeing, weaving, batik, and sewing, and dropped it. She bred show-winning Samoyeds, and dropped it. There were a host of other skills, I have a list somewhere.
The only thing she stuck with was psychoanalysis. She started studying with Freud in 1924, when she was in her late 30s, and continued as a practicing psychoanalyst into her 80s.