My girlfriend owns a 2006 G35S Coup. I've been reading a lot of helpful knowledge from y'all and I want to thank you.

My question is: She has been having a transmission problem, upon releasing the clutch the transmission will not in engage right away. She tells me she doesn't recall the transmission or clutch fluid ever being changed. She doesn't drive it very hard (baby's the car). I've been wondering if I should try replacing the fluids first? Any thoughts or suggestions..... PLEASE!!!!