Hi Robyn,
Assuming that Caroline died in 1847 or 1848, on the grounds that she married in 1847 and Alfred emigrated with his aunt and uncle in 1848, the only death I could find during this period in Sussex was:
June Quarter 1847 in East Grinstead
Caroline Ellis
Vol 7, Page 264
In 1848 two Caroline Ellises died: one in Wandsworth and one in Dewsbury.
Dimps