This is of interest to me as I'm a great tea drinker myelf !

By JA's time, tea was an important part of life that people tended to call leaf infusions' 'tea'.

For centuries, the English had drunk herbal infusions (called 'tisances') but with the coming of Chinese tea, everything was called 'tea'.

People drank teas from other garden herbs such as mint, chamomile, lemon balm,sage, majoram and lavender as we do today.
Mrs Austen probably grew herbs in her kitchen garden.

People also made tea from many plants with less than pleasant sounding names--St John's wort was considered 'good for jaundice', Colt's foot 'for consumption' and Pennyroyal for kidney stones ie 'the gravel'.

In Dandition, the Miss Parkers' drink herbal tea.

Mrs Austen drank dandilion tea quite alot for bilious complaints-her liver and digestive difficulties.
Apparently, Jane was somewhat skeptical and often less than sympathetic of her mother's frequent health complaints.

-from 'Tea with Jane Austen'. pp 58-60.
Kim Wilson
Jones Books. (2004)