All depends on what type of person they are, some people would love to blow the 5k on partying, experiences, taking courses, learning a new skill, material possessions. Me personally, I would have loved to get started on my first investments. I think, seeing an investment grow can have an extremely positive impact on your life and your understanding of wealth and how investing and compound interest works. Whatever she does, I think she should at least set up an account with Degiro/Trading 212 or another alternative cheap broker, and invest even if its 100euro in an ETF. It would be a great learning experience on the power of investing.