Aaron.
Welcome to the forum, we will do what we can to help and encourage.
Tagging
@daisy1 for the standard newcomer information.
In your research, have you looked at the Low Carbohydrate High Fat eating style? Similar to Atkins.
That has much lower carbohydrate targets.
You are looking at maximum 50 grams per meal (I assume 3 meals) and 30 grams per snack. If we assume two snacks (morning and afternoon) that gives (3 *50) + (2 * 30) = 210 grams of carbohydrate per day. That is pretty high carbohydrate and probably not ideal for a T2 diabetic.
If you were to go the low carbohydrate route many follow on this forum, you would be looking at closer to 50 grams of carbohydrate per day. Some go as low as 20 grams.
Your mother is on Gliclazide which encourages the pancreas to produce extra insulin. Because of this she would have to be very careful when lowering the total number of carbohydrates eaten because with less carbohydrates there is less glucose in the blood and she could experience a hypo. So gentle steps.
She may be a little late for reversal, but not for achieving normal levels of blood glucose, which can look very similar.
Your biggest issue is that she is very used to a high carbohydrate diet.
[As a side note, carbohydrate is turned by the body into glucose. The body can't store much glucose so insulin is used to turn it into fat. So eating lots of carbohydrates can result in storing lots of fat.]
Please look at the low carbohydrate forum where there are loads of suggestions about how to replace high carbohydrate favourite foods with low carbohydrate alternatives.
You have come to a good place for advice. Take your time because it takes a long time for it all to sink in. Ask loads of questions.