In 1541, Catherine Howard had begun a physical relationship with Henry's favourite courtier, Thomas Culpepper, and Jane Boleyn went out of her way to encourage this relationship.
Catherine wrote to Culpepper in a letter that was to be all their undoing:
“praying you that you will come when my Lady Rochford is here”
If Jane had anything to do with Anne’s downfall she must have realised that she was lucky to escape in 1536, and if she didn’t, then she doesn't seem to have learnt anything from the whole affair. Jane must have known what would happen if Henry found out that she was involved with Catherine and Culpepper and when the affair was out in the open each woman blamed the other. Maybe Jane had it in for Anne and didn’t need much encouragement to tell tales or maybe she was just repeating gossip, but she walked right into the Culpepper affair with her eyes open.
I have never been able to work these women out, they were either naive or actually incredibly stupid.
Following their arrest, Jane Boleyn was imprisoned in the Tower of London and Catherine Howard at Syon Abbey. The night before her execution, Catherine is said to have spent it practicing laying her head upon the block, and Jane, she no doubt was still in the throes of a nervous breakdown.
Both women were beheaded with one blow of the executioners axe and their bodies buried in the chapel of St. Peter ad Vincula.