Who was jenny geddes in Robert Burns life?

Jenny Geddes was Robert Burns horse.

The horse was named Jenny Geddes after an Edinburgh women who had famously defied James Hannay, Dean of Edinburgh by throwing a stool at his head. She was upset at the Anglican book of common prayer being used as opposed to Church of Scotland teachings. There was a widespread fear in Scotland of Roman Catholicism becoming the primary faith and Anglicanism was seen by many as a step towards it.

Due to her stool throwing, riots ensued inside the church and these scenes were replicated across Scotland over the next few days which eventually ended up with the signing of the National Covenant, meaning presbyterianism was to be teached inside Scotland's churches.