Up to you really. I have a great relationship with my two adult half-siblings. We met in our 30s.

This is an old thread but I will just say that two half sisters (lost to adoption) found my family when I was an adult and both have enriched our lives enormously. 1 lives on the West Coast so I don’t see her much but the other is part of our lives frequently and she and her husband are by child’s most loving and present aunt and uncle. I am so lucky and so overjoyed that we are family.