If she does decide on a smaller trip in August and postponing Paris until later in the fall (which I would highly suggest as she will not get the true Parisian experience in August), you might suggest Montreal/Quebec City for her birthday. It is only 9k Avios points per person round trip from NYC to Montreal (she could also rent a car and drive). She could get the 50k British Airways card and use the remaining points for a couple of hotel nights (and/or use the avios points for the car rental).