My MIL could resent me - her son moved 140 miles away to marry me. Then her daughter loved it here and met a bloke from the NE and moved here too.
But MIL has welcomed me with open arms, as has FIL.
They are not like my parents were - they are younger - mid 60s whereas my parents would have been early 80s now. They are educated- both ex-deputy Heads (him primary and her secondary) but have things in common with my parents and the same values, just more socially confident. They are quite moral - we were not allowed to sleep together in their house until we were engaged; we were 30 
At first, nice as they are, I kept my distance. MY dad had just died and I had my own mum and they were 2 1/2 hours away. We got on well, just were not that close. When my mum died 3 years ago, MIL was the one person who I could bear to let help me and she was wonderful. She drove straight up here and just quietly and in a sensitive but practical way helped me sort out my mum's flat. She was fantastic.
Her view is we have our own life, we are adults and it is ours to live.
When I got pregnant she minded her own business and did not once interfere. We had said no one could come and see him for the first week because we just wanted some time but as soon as he was born we both wanted them to see him and DH rang them and they were on the next train and at the hospital that night, over the moon, and then on a train home.
She is funny and kind and stands no nonsense from DH (but loves him to bits) and likes that I have the measure of him. She thinks I am really good for him but says she has no idea how I put up with him (he is a lovely man). She is definitely in charge in their house. Quite unusually, FIL stayed at home with the children when DH and SIL were born and took a 4 year break from work to look after them and she worked full time throughout her career.
She and FIL are slightly eccentric and I certainly couldn't live with them - there are things that drive me barmy- but I have grown to love them. They are great grandparents. Don't know how much more difficult it would be if they lived closer - we see them about every two months and DH speaks to them about 2 or 3 times a week.
If she was moaning about me it would be about both of us and how we waste money on things we don't need. She thinks I have encouraged that side of him. needs no encouragement