I think you are correct that they are suckers as the the grafted stem is definitely thicker. I would wait and see how the fruit is on those other branches before removing just to be sure they are not worth saving.

Why did you cut the leaves off?

Thank you Denise and John for your input. I may have to wait to see before I cut the other branches. I cut off the leaves from a long branch that was way longer than the other two branches. I was told to mulch the leaves. Plus it was fun for my toddler to do.

Myra, I am not sure allowing your toddler to cut your leaves was a good thing. He/she may think it's ok to do again. lol.

The long branch was probably what we call a watersprout; it is normally trimmed back to the level of the general canopy.

I can only see one graft. Leaving leaves to decay is a really bad idea. Your just encouraging pathogens, insects and ethylene which at the wrong time can encourage pre-harvest fruit drop. To put it into context, where I live a lemon cost 50 cents in the grocery store. For me to grow one lemon it probably cost a hundred dollars a piece with all the time, money and effort spent growing indoors. If your not entirely happy with the graft just buy a new one. Chock it up to experience.