There is nothing wrong with the Hybrid. In the scenario described (at a light on an incline) the hybrid engine has turned itself off and the CVT transmission is essentially in neutral. When she lifts her foot off the brake the car rolls back, the engine kicks on in “low forward” and there is some shudder. I think this is normal. Suggest 1) be quicker to the accelerator or 2)brake with left foot in this scenario and give it a little gas before releasing brake.
I have a 2004 Civic Hybrid. This car is subject to a transmission problem which hasn’t reached the state of a recall but if you complain to the dealer about a “shuddering” problem, there is a series of fixes which the dealer goes through. It starts a a low frequency rumble and progresses to become a louder and more pronounced vibration from a start under acceleration or in reverse up a hill.
There is a service bulletin on the “shudder when starting from a full stop” complaint. It is a transmission problem, and the dealer should repair this for free.
Regarding rolling back after stopping on a steep uphill and the engine shuts off, this is to be expected. Try the technique that drivers of a stick shift learn - hold the car still with the hand brake until the engine restarts and engages.