I recently saw the film Nannerl: Mozart's Sister (2010). It is the work of the French filmmaker René Féret and half his family. Yes, when you watch the credits roll past it soon becomes apparent that many of the actors are family members of the Féret clan. Two of the leading actresses are his daughters. And father René wrote, produced and directed the film.
There aren't many films that involve parents directing their own kids. It must be an "interesting" experience for all concerned. But there many other ways in which artists combine intimate relationships and their creative work, some with outstanding success, others that end in tears.
The real-life relationship between Wolfgang Mozart and his father Leopold was a complex one. The elder Mozart was himself a respected musician but also drove his children very hard as they spent most of their childhood on tour.
Conductors seem to have a penchant for romantic relationships with prima donnas, as do film directors with leading ladies. The composer Gustav Mahler was infamously harsh on his wife when he forbade her to compose until near the end of his life. Richard Strauss on the other hand seems to have been the subject of a tyrannical wife (a former singer). Benjamin Britten and Peter Pears formed one of the most famous and productive musical/personal relationships of the twentieth century.
The question remains whether the intimacy of these various relationships in any way enhances the art making of the people concerned. In answering, it is difficult to generalise. Clearly in some cases it does. In other cases the mixing of the personal and the artistic clouds the latter. It can be a highly rewarding exchange. René Féret must have felt some sense of pride in the acting skills of his daughters. At least let's hope so! It certainly must have brought an intriguing family dynamic to a film about the relationships in one of the great musical families. Artistic lives imitating artistic lives!