Just some thoughts -

If she's close to goal, 1/2 pound a week is a good rate for a woman who's 5'2".

How much protein does she eat, in ounces of meat per day? or, grams of protein if you want to estimate that. that can affect how much ketosis, for some people.

does her job involve heavy lifting as well as walking? that will make a difference - it's like strength training plus cardio every day.

Is she up to measuring inches as well as pounds? the combination can tell you if you are losing fat.