"And getting married this autumn was certainly an additional incentive to spend rather more time in England"

This quote by Jill Dando suggests that she was preparing to get wed in the fall which this was a reward for her to invest more time in England. This might suggest that she was living abroad and was preparing to go back to England to get married, or that she was already living in England and wanted to invest more time there in preparation for her wedding. It might also recommend that she was planning to marry someone who lived in England, which she wanted to spend more time with them before the wedding. Whatever the case, it is clear that the possibility of getting married was an important factor in her choice to invest more time in England.