What is considered "normal" can vary significantly depending on cultural, familial, and individual circumstances. In many cultures and families, it is not uncommon for young adults in their late 20s to still live with their parents and share some household responsibilities, including laundry. It could be due to financial reasons, cultural norms, or simply a close-knit family dynamic.
However, in many Western cultures, there is a societal expectation that by the age of 28, individuals should have gained more independence and self-sufficiency, including managing their own household chores like laundry.
Ultimately, what matters most is the comfort and agreement between the individuals involved. If the 28-year-old and their mother are both content with this arrangement, there might be no issue. However, if either party feels uncomfortable or wants to encourage more independence, it might be worth discussing and finding a suitable balance that works for everyone.
Each situation is unique, and there's no one-size-fits-all answer. Personal circumstances, cultural norms, and family dynamics play a significant role in shaping these decisions. As long as everyone involved is content with the arrangement, there's no inherently right or wrong way to handle household responsibilities.