Want to Shoot Macro - Having Issue with Lens Decision

What 105mm lens did you get? If it's the new one it should get pretty much to 1:1. For the flower this mean it would be on the sensor at pretty much the same as its actual size.

The 24-70mm lens has a x0.27 max magnification. The 105mm Micro has a x1.0. This means that at max amgnification (i.e. closest focusing) you could get approx x16 bigger with the 105mm lens (x4 on each dimension). Your example looks at most x4 bigger (i.e. x2 on eahc dimension), so it can't be max magnification and you should have been able to get closer.