to pick at

[constantinusphilo]

She looked at the bag in her lap and picked nervously at it with a gloved finger.
The Maltese Falcon, by Samuel Dashiell Hammett, p. 7
Is it like 'poked'?

 

[jutfrank]

It's more like 'fiddled with'. Imagine the way she would play with her bag to calm her nerves.