Her acting IS terrible.
Like all of Trek is chock full of great actors
Yeah, maybe she's not the best actress going, but she's fine for a fun bit-of-fluff TV series. I don't ask anything more of my casts
Most of the time it is also due to some very bad lines the scripts have. Her acting shined from time to time though. I really liked her in Awakening, In a mirror, Darkly or in Twilight.
Obviously she's outshined by Linda Park, but that girl also had to learn some very weird lines (as in alien languages).