I like these better with "already":
(a) When she came, we had already been talking for an hour.
(a') When she got here, we had already been talking for an hour.
(b) When she came along, we had already been talking for an hour.
(c) When she came over, we had already been talking for an hour.
(d) When she appeared came in the door, we had already been talking for an hour.
(e) When she dropped by, we had already been talking for an hour.
Also, for me "she" and "we" seem to clash a little--it takes a second to decide/conclude that she is not part of the we. Replace "we" with "my friends and I", and already seems less important:
(a) When she came, my friends and I had been talking for an hour.
(a') When she got here, my friends and I had been talking for an hour.
(b) When she came along, my friends and I had been talking for an hour.
(c) When she came over, my friends and I had been talking for an hour.
(d) When she appeared came in the door, my friends and I had been talking for an hour.
(e) When she dropped by, my friends and I had been talking for an hour.
(d) "appeared" would not typically be used in this kind of situation.