Reference:
She is not in a particularly senior position, but I think she feels that because she has been there for many years and is popular with her team, then she can behave how she likes with newcomers, or people she perceives to be weak/insecure/have an inferiority complex.
I sympathise with you Sheryl. Really can't stand people like this, it sounds like she is deliberately throwing her weight around knowing it will make you uncomfortable.
I've worked with women like this before....most of the time in the past I've just tried to ignore them, knowing that they probably have quite a sad life to get kicks out of intimidating and being patronising.
She might be looking for a reaction from you, so I'd say the best thing to do is to smile sweetly, keep the words short, and get on with your work when she gets up from her desk.
It's very difficult I know, but it will probably have more of an effect on her than you might realise.