Be rolling in money/it
Definition 1 of 1
Pro Tip 1/3Figurative Expression
The phrase is not literal; it means having more money than one needs, not actually rolling in physical money. 
With that lottery win, she's rolling in it now.
Pro Tip 2/3Colloquial Usage
Commonly used in informal conversations among friends or in non-professional settings. 
Looks like you got a bonus, you're rolling in money these days!
Pro Tip 3/3Expression of Envy
Sometimes used to express mild jealousy or admiration when others have much wealth. 
Wow, they must be rolling in it with a house like that!