The 42-year-old actress is married to "James Bond" star Daniel Craig. Henry is her son from her relationship with director Darren Aronofsky.
She said that she is determined not to push him into a career direction he may not want, reported Femalefirst online.
"He is really into science and batteries and magnets and how things work. He is just finding his own way but he has so many people around him in the arts that he will probably rebel and become a banker," Weisz said.
"I don't push him towards anything, I just let him be," she added.
The actress also said that she finds it difficult to relax when she isn't working because she does not enjoy being alone.
"With difficulty. I am not brilliant at being on my own - I don't have a hobby. I don't play guitar or knit," she said.