0Neither, in my opinion.02br 02br 01i00She had been in the sun too long.02i02br 02br 01i00She had stayed in the sun too long.02i02br 02br 00But not "was staying" or "had been staying."0-
0Hi,02br 02br 00More natural and common, I think, would be to say or write02br 02br 01font00Mary fainted because she stayed in the sun too long.02font02br 02br 00The semi-colon hints at the reason, but 'because' states it explicitly. Why bother just to hint?02br 02br 00Best wishes