As for her ‘nursing’ prowess, the young Seacole learnt herbal healing from her mother, who worked as a ‘doctress’ (healer), and gleaned informal tips from doctors staying with her family.
Her expertise in this area, however, can only be taken on faith. There is no hard evidence.
As for the herbal ‘remedies’ she used for cholera, for instance, she described in her memoirs how she added lead acetate and mercury chloride. Both are highly toxic, cause dehydration and produce the opposite effect to the treatments used by doctors today.
I am too old to have learned about Seacole at school, it’s a recent phenomenon this lauding of her. And it’s worth reading that piece in full because the generally told stories about her seem to be entirely bollocks.