It sounds likely that she malabsorbs severely. It also is likely that the first B12 result was not accurate and that she may have been lower than it suggested.

Many doctors do not know that people who malabsorb severely can absorb about 1% of a very large dose. So many doctors would assume that she does not malabsorb severely.

Even worse, many do not know that even more people cannot absorb B12 from food, but can absorb just fine from a supplement. Those people would increase their level MUCH faster than she has on even a smaller dose than that.

I would continue with at least that dose (actually, I would increase it), and, over time the stores should become filled and the level increase a great deal.

It is also likely that she does not absorb iron efficiently. If she has lost intrinsic factor, she probably also lacks sufficient stomach acid to absorb iron well.

Has she had a ferritin test to see what iron stores are?

rose