That's kind of hypocritical from her side - if there's a problem she should had just admit what bothers her instead of the enigmatic "you're hard to work with". Well, not enough feedback here to make it easier for both of you.
Let's hope she realizes soon and stops being all antsy about it.
There might be some truth to what your mother says.
I had stumbled upon a research analyzing such workplace relationships and it actually mentioned something similar to this. Too bad my memory won't let me remember much more but I usually ignore most studies anyway as they seem too random.
