Yes, it would be very nice to see less grain in both shots. Flowers hint at emotions describing delicate, elegant, perfection . . . Graininess hints at rustic, antiquated, rough . . . The two just don’t match well, unless it is obviously intentional.
I would therefore suggest using an external speedlight to add more light through bounce-flash. It would not only allow for a lower ISO number, but it would add softer light.
Like @timtam, I love the royal color. Perhaps you could take out the brown color in the water (in the second image especially with the better angle of view) with Lightroom’s HSL sliders or the Brush tool.