In-laws Prefer Some Grandchildren Over Others..?

Very common.
Usually if the in-laws have a favorite child then those grandchildren will end up getting favored. Or if one set of grandkids lives nearby and the grandparents see them more often then they will be closer to those kids. Or if son-in-law or DIL is strict about access to kids they will gravitate to what is easier.
There’s not much you can do about their attitude, but make sure that it’s not blatant in front of your daughter. If they visibly discriminate then ask your husband to have a conversation with his parents.

 

Absolutely common. I get your worry for your daughter. As a second-class grandkid myself, I can tell you that eventually she will understand. It will hurt a little bit but she will learn that it’s not worth it. It will make her be more understanding to you.
Bad side-effect? Hope she doesn’t tell her angry paati that ‘you, me and George bush won’t die that quickly for all the sins we made’.

 

THIS.
Golden child's golden grand child.

There is sometimes a scape goat child which is even worse. Take expenses from the scape goat yet favor the golden child.