My children were the first grandchildren on both sides. either my bro nor DH's sister had a baby until after Riley was born! My poor DDs had no cousins until they were 15 and 7!!
DD1 was the first great grandchild all round too and had my mum's parents until she was 5 (my grandad) and 13 (my grandma and DH's pop) and 15 (DH's grandma)
Sadly my brother's kids and my DS will never know my mum as she died 7 years ago.