JavaScript naming and grouping
To start off, I can't see a single semicolon being used here. You should always close your statements with a semicolon. 

Also I can't quite understand what you've done here:

'click .hint-text': function(e) {
    e.preventDefault()

    var currentHintId = $(e.target).attr('id')
    Session.set('currentHintId', currentHintId)

    $('.hint-popup').show()
},


Is this a property in an object? If so why have you named it 'click .hint-text'? Give it a proper name such as togglePopup or something along those lines to make it more obvious what it does. Now it's just confusing. 

And for the other function you could name it submit(whatever you're submitting).

If you included some additional markup it would help your question a bit.