Another book I read while away in the New Forest.
Starts with a girl about ten (?) running away from home in London, so that she can't be evacuated to the countryside during WW2. She meets a young man called Sam (?). Her grandfather (William) was a famous actor in a nearby theatre. She is raised by her grandfather and his Scottish sister -in-law, after her mother's death. The mother committed suicide in front of a bus after apparently being deserted by an Italian boyfriend. It later turns out that he didn't know she was pregnant. He appears later on, is from Florence.[I think he brings her a present he has made - though I could be confusing this with another book - Glassblower of Murano?]
She's unimpressed at the time, but later goes to Italy. Oh yes, he dies in a convent - she sees him not long before his death.
There's also a woman who makes costumes who is a surrogate mother, and acts as a fairy godmother financing her studies, under the pretence of money from the girl's father.
For a while she is involved with a suave successful actor, who can't cope with real life, and has lost himself in the characters he plays.
The protagonist ends up as a scenery painter, and costume designer, and works with Sam. Romance, of course.
All very bitty and I can't recall author, character names, title, publisher...anything!