Hortensia learned the way of potions from herbalist witches and the fundaments of medicine
p.s. according to my research the wife of Van Helsing was daughter of the 11th Lord Tennington
My good, she looks so beautiful, so hot, so... feline. And I love it!
In fact, that image of her with a gas mask and a bomb gave me a good idea with a Van Helsing fanfic what I'm writing: She can make molotov bombs for her husband, as well working with poison plants.
She's really a femme fatalle with a gentle heart.