In buildings with shared amenities, whether large or small, monopolization of those places by certain people is a very common problem. It involves one or two people claiming an area for which they do not have exclusive right of possession. It’s essentially stealing, because to get exclusive use they should be paying more rent money. Based on what I’ve observed, trying to get along usually does not work because the claimers will be aggressive about trying to defend their territory.
It would be helpful to know what exact language is in your lease agreement about use of the kitchen. You will need to tread a very fine line about using the kitchen according to your present needs while being extremely careful to be very even tempered with your neighbor. Any time she gets angry you need to calmly document the incident and report it in writing to your landlord. As far as having to move to solve the conflict, that advice should apply as much to her as it does to you. It does not matter who was there first. If she is claiming too much of the kitchen, you need to inform her firmly but politely that she will need to change some of what she is doing in order to respect the rights of her neighbors.

