A large geographical distance between 'close' family can strain/break relationships.
My husband's mother moved to Lanzarote when our children were small. She said it was only three hours away? We're north of England.
She said that she would get to see the Grandchildren more often as she would send them money for flights and that we could put them on the plane and she would meet them at the airport, every school holiday. It never happened. She said that we could (H and I) visit for two weeks every year - we never did as we'd been there numerous times and had ticked it off our destination list.
When she was sent a picture of her newborn great granddaughter, her first great grandchild, her response was 'isn't she big' - not beautiful, not adorable, not cute, but big. She weighed 6lb 12oz, so no, not big at all.
She came back to the UK a few years ago and now lives 10 minutes away. She thought she could just slot back into our lives. She'd been gone almost 20 years; all through her grandchildren's childhood. They had their own families when she came back to live here. My daughter (now 30) saw her in the town and MIL walked straight past her - didn't recognise her own granddaughter, despite always having had recent photos and contact through social media.
She came to my mother's funeral and, when reminiscing, mentioned that it felt odd to not even know such things like her grandchildren's favourite food/favourite colour/interests. She thought it was an amusing anecdote.
My husband resented that she couldn't be bothered to maintain a relationship with her own family. We were out of sight - out of mind.
He can't bear to be in the same building as her now. Due to her absence and non contact the relationship no longer exists. The distance that she put between herself and her family all those years ago remains the same.