Did she tell you why she was doing it or did she only give you some platitudes and thanks?
Because a lot of people are not used to be talked to, and even if they are all rage inside the car, they get scared quite fast when someone fully geared on a motorbike knocks on their window - and tbh I think it is pretty understandable.
Still, good on you, I usually just let them go and change road - when feasible. There’s no need to waste a good riding day with some knucklehead.