When I squint I feel like you've really focused on your values and it shows! The special attention you paid to the shading really paid off.

I think the stem might not be that thick. I think if you were to do a much lighter sketch next time before doing the "final" you could have the opportunity in the practice round to get that closer before committing. As long as you sketch really lightly it's easy to erase what you don't want and the sketch will give you some nice guidelines for the final.

I'm glad you spent the time shading around the petals to give them dimension and you've placed some nice details in the leaves as well. It's a success!