Complex sentence: It is claimed that in 1927 she fell in love with the homosexual Russian painter Pavel Tchelitchew; the relationship lasted until Helen Rootham underwent various operations for cancer in 1928 and became an invalid.
Split into simpler sentences: It is claimed that in 1927 she fell in love with the homosexual Russian painter Pavel Tchelitchew. The relationship with Tchelitchew lasted until Helen Rootham underwent various operations for cancer in 1928 and became an invalid.