Not a parent but the child (21f). It took a while for my parents to trust my grandparents with my sister and I. Paternal grandparents didn’t make much of an effort and had to be pushed to do things with us while we were staying at my uncle’s house (which was around the corner from them) - they have since both passed away.

Different story for my maternal grandparents though. To clarify they’re divorced and let’s just say they had to regain my mum’s trust after s*** happened. Grandpa ran away with granny’s bff, abuse by step dad, grandpa didn’t listen or believe them (mum and her late sister), granny refused to believe them, evil entitled step sister (step mum’s daughter from 1st marriage) who is extremely jealous of my mum and a totally bully to step mum but acted like daddy’s little princess to her bio dad (step mum’s 1st husband) and to top it all off My Mum’s sister died in a car accident 3 weeks after my sister was born and they FOUGHT about who was responsible for paying for the funeral. My dad took charge, planned and paid for the funeral to help my mum to honour her sister. Grandpa has now passed away (which was sad). Step dad passed away in pain from cancer (I don’t normally say that about cancer or condone someone dying in pain but step dad was abusive and evil. May Step dad rot in you know where.

But you wonder why it took a while for my parents to trust them again. My bio maternal grandparents and step grandma apologised to mum and she forgave them. So my mum mended her relationship with them and my parents trusted us with them (I think they worked through everything while my parents were dating or during wedding planning since they both wanted to be there for Mum’s wedding).