I suggest she stop focusing on calories and start focusing on nutrition. We have 31 essential nutrients, and you can track them too. Trying to get all these is an effort well worth it.

When you only focus on calories, you might not be getting all of these. Start with 1-3 of them and see how it goes.

For example, selenium can be obtained with a few Brazil Nuts each day. Iodine with fish, eggs, and seaweed among other things. Going for these items will broaden her diet.

Big congrats to your mom, and thank you for the compliments, @moz333. I too had a time when my weight got too low, but now I am settled in after 8 years.

Please reply again after she looks at this with progress or any questions.