My loveliest colleague beats the crap out of her desk, keyboard, mouse, phone (phone smashing!) etc etc., and yes it's a little distracting (as is the fax, the footfall, the photocopier, the coffee machine, people bloody BREATHING - been one of those days) but that in itself is not enough justification for you to be so mad.
I guess though it's in the little things, the cumulative effect, I understand that... BUT FGS woman you're leaving tomorrow!!!!!!!!
Let it be someone else's problem.
I will say though that if she's reduced you to tears by making comments on your age, much as it's not a nice thing to do, then it makes me wonder if you've just had enough generally and she added to your feelings of shiteness rather than being the cause.
I'm not saying it's nice to comment on anyone's age, especially if you don't know them or know how well they'll taking teasing (my colleagues and I all know our limits, there's banter, but it gets dropped quickly, never goes too far) but new girl makes you cry by commenting on your age???? Be proud of your age, equip yourself with comebacks.
Leave tomorrow feeling doubly happy, happy that you're moving on, and happy to leave her behind. If she's that bad, she'll get hers...
In fairness to you, she sounds like a twat "sympathetic ear"??? FFS, the only people who say that particular line are those that generally don't have one!
Chin up. You could compose a scathing whisper for when you last shake her hand, but would it make you feel better? If so, I'm sure there's a fair few people around here with the wit to compose a chilling whispered 'farewell'. 