No longer a newbie, moving up!
What does the histogram tell you? If the histogram indicates blown pixels, then yes.Does the image look blown out to you?
I have a couple of reflectors but if the image is blown out am not sure that I want to add more light.
No, do not add more light. There is enough light already on the tops, so if anything, there may be too much light. When you stop down, that is when you need to add light (such as a reflector or low power flash) on the near side to light the near side ONLY a bit more. Be careful how you position the reflector so as to not overexpose the tops again.
Thanks very much and will try again ..