Question about not correcting resource guarding

I have a 12 week old Bernadoodle. She's one in a long line of puppies that I have owned/trained over my lifetime. I've tried really hard to keep up with the latest training techniques, and to make sure that whatever I'm doing with the current dog I'm training matches their personality and meets their individual needs. I had a conversation with a professional trainer today that has left me a little perplexed.

I took my puppy to her first puppy socialization/training class today. She ended up being the only dog in the class, so it was a private session with the trainer. During the session, the trainer asked whether there were any specific issues that I wanted to discuss. I mentioned that my husband and I had noticed some resource guarding behavior (growling at us when we were around her food). I explained that I had worked with her a bit as soon as we noticed the behavior, and since then, we had not had any issues. The trainer asked what I had done, and I explained that (as with all my puppies) I work on desensitizing from the get-go. It looks like putting my hands near their food bowl, talking to them while they eat, and sitting close to them. Sometimes I hold the bowl while she eats. Sometimes I pet her or give her a pat on the head. I also occasionally pick the bowl up for a moment, practice a "wait" command, and then place the bowl back down.

One of the reasons I focus on this skill first with my dogs is that I have kids, including toddlers, who don't always understand or listen when I say to leave the dogs alone while they're eating. I want to make sure I head off any issues before the dogs become bigger and can potentially cause more damage. I feel like it's an important part of the dog's long-term well-being as well. They could be at risk if they have behaviors like these that aren't taken care of early on.

The trainer did not seem to agree. She stated that the method I use is old school. That I would never take a steak dinner away from someone who was hungry. She said that the reason I'd seen the behavior diminish was because the dog loves me and shut down in order to avoid disappointing me. That she should be allowed to growl to show us that she wanted us to back away from her food. She stated that the dog should always be fed in a kennel and that the children in the household would then not be able to disturb her while she's eating.

I'm not diminishing the trainer in any way. I believe that everybody has their own methods and opinions, and that is totally fine. But I also firmly believe that a dog is a pet, not a person. I will never allow her to go hungry, and she is never denied food. But I'm not willing to allow any animal to live in our home who hasn't learned manners.

Am I completely off base here? Have I missed the mark on this particular training ideology? If so, I'm open to helpful suggestions.