So sorry that you had to experience that kind of behavior from someone you thought you were on good terms with. I have a similar problem with my
neighbor's grandson who came to live with grandma a few years ago when she sold some property and acquired some money. I could go on ,but....
Anyway, try putting yourself in her position for a moment. She lives there all year round, it's quiet at night, she probably goes to bed early. She may resent the fact that you come up on weekends and disturb the quiet that she
is used to. The barking dog probably woke her up. When my dogs bark and wake me up I deal with it, when my neighbor's dogs wake me up I get annoyed. This has probably been building up for some time with her. She should have brought it to your attention in civilized neighborly manner to avoid bad feelings. That being said, I would begin to document each incident just in case and maybe keep the dog in the house after dark so as not to exacerbate the situation.
Good luck, hope this helps.