Some short remarks: this is really an issue your doctor should deal with.
If for some reason the anaemia is quite “chronic” or stubborn one should always think about a deficiency of other elements as well except from Iron .
Some minerals may be lacking such as copper or another important issue maybe : a low stomach acid [hypochloridea]
Hypochloridea is extremely ignored by doctors even gastroenterologists.
This low stomach acid can cause malabsorption for iron as well as folate, vitamin C and more.
In that case supplementing with betaine[and pepsin], at least for a while may be the solution.
In the long run herbs can be used such as dandelion, artichoke etc but you better discuss this with a professional in that field.
In case you wish to order [discuss with your doctor]