We married in 1972, a smallish church wedding, but nephews, nieces, aunts, uncles were invited.
When my cousin married in 1976, it was no children. My sister took umbrage, she had 3, and didn’t attend. I was close to my cousin, the same age, and DH and I attended, my sister looked after our two but we would have asked the in-laws to if she hadn’t.
Fast forward 30 years when said sister’s own children married, no family members, let alone children, were invited.
A different matter when they were forking out for the wedding.