Hi, and welcome!
So first off, separation anxiety is really normal in babies. They start to develop that idea of object permanence and at that age aren't actually sure if something is coming back once it disappears! Parents are often encouraged to play games like peek-a-boo in order to help their LO develop the idea that things come back when they disappear. Does it help if you try to reassure her with your voice?
It's also possible that she's on the verge of some sort of developmental leap -- crawling, standing, etc or T hat she's in some sort of teething pain and needs some more reassurance. Will she tolerate being in other places better? Sometimes at that age, I found my babies were content if they were sitting upright in a high chair or somewhere where they could actually see what was going on.