That's one of my favorite parts about flying. The wings and engines shaking during turbulence.
It's great during landings and take-off when the flaps shake on there own.
Honestly, I'd be worried if they weren't. Because that'd mean they will snap.
Just like a wooden roller coaster, if the wood is not vibrating and shaking side to side, that's bad, it means the rollercoaster is going to snap.
Just my opinion.
"Generosity is giving more than you can, and pride is taking less than you need." - Khalil Gibran