Great question. The short answer is no she does not need to avoid it.
The longer answer is that anise (Pimpinella anisum) is considered to be both a vegetable and an herb. It is related to fennel, both of which do have a licorice-y flavor. Aniseed oil is apparently sometimes used to deepen the flavor of licorice candy. However they are different plants, and plant families, and anise is not considered to be a blood pressure raising herb.
As always I would like to point out that if you have a serious health concern, such as very high blood pressure, it is important to be under the care of a reliable health care practitioner.