As Edie suggests, it’s not quite time to worry, yet. Give things another couple of months before assuming there’s a problem.
Also be sure to look at inflammatory markers (white blood cells, C-reactive protein, ferritin, and the like), HbA1C, HOMA-IR score, and the ratio of triglycerides to HDL. If they are improving, then you know that things are well. In particular, the triglycerides are not so much of a problem if the HDL has gone up to match. A ratio of 2.0 or less (0.9 or less in European measurements) indicates minimal cardiovascular risk.
In the meantime, make sure your mother is getting enough salt and staying hyrdated. This will help with her electrolyte balance and blood volume, and might possibly help improve her blood pressure. Recent studies have shown that we need more salt than the official dietary recommendations would suggest.
Another thing you can do might be to look carefully at what your mother is eating, and verify that her carb intake is really as low as you think. There may be hidden sources of carbohydrate that have been overlooked. This is not as much of a concern if she is eating whole real foods, but if there are any processed foods in her meals, they could be a problem. It’s something to double-check, in any case.
Lastly, if you can afford to get a home ketone meter, you could double-check your mother’s ketone levels and make sure that she is indeed getting into ketosis.
Let us know how things go.