Clara Wieck / Schumann couldn't have met Franz Liszt in Paris during her journey, since at that time 1838/39 Liszt was working in Italy. Furthermore Wieck / Schumann and Liszt already met in Vienna in 1838, before the Paris journey, and were corresponding ever since.
In the movie Clara Schumann met her father the first time after the marriage in 1845. However in real life the already met in 1843 where they tried to figure out peace between Friedrich Wieck and Robert Schumann.
Schumanns daughter Elise is portrayed as the older girl while Marie is shown as the younger one. In reality it was the other way around since Marie was born in 1841 and Elise was born in 1843.
The first scene of the movie, according to the diary entry sets the scene in 1838 and shows Clara Wieck (later Schumann) in Leipzig. At that time however she was in Vienna. Also the Paris journey without her father happened one year later, in 1839.
While performing in Stockholm King Karl XV of Sweden is watching. Based on the diary entries the scene is set in 1847 while Karl XV didn't become King of Sweden until 1856. At that time Oscar I. was King of Sweden.
When meeting Johannes Brahms the first time Clara Schumann thanks him for the "Wiegenlied" Lullaby and said that the children love to sing it. The tune was written in 1868 while Brahms first met the Schumanns in the early 1850s.
When Robert Schumann mentioned in 1845 that he is working on an opera based on the Lohengrin saga, Friedrich Wieck mentioned that he should listen to other composers as well, referring to the opera "Lohnegrin" by Richard Wagner. However while Wagner indeed started working on the opera in 1845 he didn't finish the first score until 1848 and didn't presented it the first time in 1850. So there would be no way of knowing for Wieck that such an opera is in production let alone watching a performance of the Overture.
When mentioning the children of the Schumanns which send their greetings to the father, Clara Schumann only mentions Marie, Elise, Ludwig and Eugenie. However she didn't mention Ferdinand, who was 5 years old by the time of the asylum and Felix who was born only a few months before Robert Schumann went to the asylum.
In the scenes of 1845 Franz Liszt and Friedrich Wieck try to convince Clara Schumann to become an artist again and start playing in public. However Schumann didn't stop at that moment. After their marriage in 1840 she and Robert Schumann performed in Weimar and Leipzig in 1841, Northern Germany in 1842 and Russia in 1844, including meeting the Czar family.