The behavoiur should settle down as life develops a routine at home. What she is doing right now is testing every rule have ever had just to be sure that life is ok. And it is ok to call her on it saying things like the rules did not change it is still not allowed at my house; You can be as angry as you want about the new baby and all the confusion at your house but at my house you are expected to follow the rules - things like that. In essence you are telling her over and over that life is ok.
Expect that she is extra tired cause the baby wakes and cries frequentlly in the night and even if she doesn't wake up she will be roused up so not as sound a sleep. Routine is out the window right now and she is unsure what she can count on - maybe even not getting supper at the usual hour if mom has to stop to feed baby, that sort of thing.
That doesn't mean you don't have to deal with the behaviour and make her shadow you. Tell her right up that you can no longer trust her to play properly so she has to stay within your eyesight at all times till she learns to treat others with respect. She may just welcome the extra adult attention which isn't what she is getting at home.
Can you suggest she come more often than once a week. That is the only way for her to feel like she belongs at your house still. One day a week she is like a fly on the wall that doesn't matter and she is making her presence known.