Cedricby your worrying about this shows you won't be that mil.
I agree with that ^^ 
Much depends on the closeness of the family in the first place. If you aren't close to your DC, you won't be close to your GC.
My DH doesn't isn't that close to his family, so naturally my DC aren't that close to his parents.
My DCs could walk past their cousins on his side in the street. It's a terrible shame. They could also walk past some of his siblings and vice versa. My DCs could go a whole year without seeing his parents, yet they would not go a month or two without seeing mine who live in another city.
My sister's MIL is a real handful and my Dsis keeps her at bay. My BIL isn't overly fussed on visiting her, so she doesn't she the GC as much. If she wasn't such a pain, my Dsis would have taken them to see her on her own a lot more.
When she had one DC, her MIL went to see the baby in hospital and told my sister how her body snapped back into shape after having each of her DCs and she was wearing her jeans the next day.
While my mum travelled the 200 miles down to help my sister out for 3 weeks with her first DC, my MIL told my sister she was lucky to be getting spoilt liked that, as in her days she had to manage all by herself.
My mum promptly told her that yes, she too struggled alone, as my GM was I'm another country, but that's the very reason she didn't want my Dsis to struggle.
The best her FIL could do was to say not to breastfeed too long, as her DH (his son) would be missing out on them.