Hello! Please help with my finance homework!

Scenario:

Your aunt, who is significantly older than your mother, is close to retirement age. Although she loves her job as a software engineer and looks proudly back on a very successful career, she is also looking forward to leaving behind the stress and pressure of work. Her retirement savings are tied up in a very generous pension scheme and mainly invested in shares of her employer, TechStar Ltd.

Question:

Explain to your aunt why such a portfolio is not ideal and how she can achieve the same or similar return with less risk.