I agree that the caving in that your Mom is insisting on, is what is the problem. I had to be strong too! I feel for you working out what she will and won't eat. I was told that my Angel was on one food and I found out she hated it! She may have eaten it at her old home, but she didn't like it very much. I found that with her it was all about smell. If she like the smell of something then she would eat it. If not no way! lol
I went through a bunch of different foods before she settled down to eating raw and loving it! She is now at her right weight. Which is right around 46 lbs. And has more energy than ever. She had no appetite when I got her, and they told me that had always been the case. But she had gotten to eating between 1.5 lbs and 2 lbs of meat a day! With great pleasure! She is not over weight at that amount but I will continue to make sure that she stays at her peak. I think that she is just making up for lost time.
Of course our several mile a day hikes could add to her cal needs.
But to start her I first would basically blanch the meat, and then cool it to room temp. It was not cooked except for the outside skin. As she accepted that I would cook it less and less. But I did have to hand feed for a while as well. But once she decided that she liked it the only meat that I had to heat was the organ meats. Which initially I seared. But I thought that since smell was a big thing with her, I soaked it to get rid of the blood and then she was fine with the liver and such.
I also give her satin balls which she loves. Since it got cold she needed the extra that these add because we are out in the cold so much. Holistic Dog - Satinballs Satin Balls
I use the third recipe but replace the wheat germ with flax seed because I don't use gluten items on dogs. I also added coconut oil for some of the peanut butter as I like what it does for animals coats. And Angel loves coconut oil.
Good luck with the process and whatever you decide.