Some questions to maybe ask:

How do I respond to things when they did tell me in the past? (Supportive or critical kind of responses?)

Are the others in the family that know around them more physically rather than just in contact over the phone? (Lots gets left out in phone conversations I have personally noticed)

Relationships are tough & a lot ot times when we find out we didn't know something , that left out feeling hits. I have learned to not let it bother me. My daughter hates talking on the phone so will only text a little here & there. We live 1100 miles away & haven't seen each other in almost 12 years. Sometimes we just have to accept relationships with them on their terms if we want to have a relationship with them.