Is she a first time/ first calf heifer? That is more common in first time heifers... but sometimes they will all do it... and the calf naturally goes towards the front, so trying to nurse off the brisket....
Making sure the calf gets to eat at least 2-3 times a day for a couple days usually gets the cow's hormones settled down and as soon as she realizes that the calf relieves the pressure in the udder, they will get it. Good that she is attentive otherwise. Some do not want any part of it..
As the calf gets a little more steady on its feet, and knows that the cow is the source of food, it will get more aggressive. Sometimes a calf will just start nursing from the back and the cow is more tolerant.
Yeah a chute is handy... and it does not have to be fancy... There are examples of a head catch... with a board that will close against their neck, and put a pin/long bolt through to hold it against the neck... use a couple of gates if need be to contain her... But if you can get her to let the calf nurse just by catching her, then she ought to get it in a couple days...
I will try to take a picture when I go up to check the nurse cow pasture... and post it here for you.
Sometimes you can find a head catch without the chute, at farm sales... some of the older styles are not as easy to use, especially if you run very many cattle, but for a small homestead type of operation, they will do the trick when time and efficiency is not paramount.
A stanchion barn has the old head catches for the milk cows to go in... and it can be the foundation for a chute... you need some sides that they cannot get out of... or throw themselves around...