If you would like to move forward with what your trainer suggested, I would hand feed half the meal and feed the other half in the bowl. Since you are only establishing a relationship and not modifying a behavior such as resource guarding there is no need to eliminate the bowl completely at this point.
I agree with GSDRaven regarding the correlation with hand feeding and the bowl. A new dog in a new environment is at a vulnerable state and small inaccurate cues from you, such as eliminating the bowl, could possibly turn into unwanted behaviors.
She will guard it from other animals which to a point I'm okay with. I don't let it get out of hand (I back the offending dog off), but I don't consider that a fault on her part because if someone bigger and stronger than me tried to steal my cheetos you better believe I'd put up a fight.
You may want to reconsider this as being normal behavior.
This is an example of how this type of behavior can go wrong......
My 6 month old female GSD (Roxy) came into rescue resource guarding at 12 weeks. She would guard the water bowl and toys only around other dogs. We have consistently worked her through in our home and with a few very well balanced dogs.
However, Saturday I turned my attention away and didn't realize there was a water bowl under a table. Roxy jumped on a Boxer-Pit mix (a dog she has worked extensively with on resource guarding) and started a fight, simply for just walking in the area of the bowl, They were both dragging leashes which allowed for a fast reaction time and luckily no wounds from either dog or people.
But you can see how dangerous this situation could have been.