I think Belle has already taken control of her life, though. She may very well have spoken her mind to Regina when she had her in captivity, so there may not be much more to say. I'm not sure what telling Regina off would accomplish apart from creating an even more awkward situation. It's not like Regina will care about anything Belle has to say, so it won't really change anything. Belle seems to be the type who would rise above it. Sometimes the best revenge is living well, and it would really burn Regina to see Belle and Rumple happy together after all she's done.