Load Toad
If she had a partner that unstable - we can equally reason why she was away travelling.
Quite apart from not knowing the full (or even the half) story, you would be surprised how many people take their own lives 'out of the blue'. The greatest number of families that I have met are totally shocked by the event and had had no warning signs.
There are some who try and fail and thus alert their family but the most recent case I dealt with (two weeks ago) the family had had zero warning and the person was behaving as they always had. I recently heard of a case where a mature woman spent the evening playing cards with her friends as they often did - left at the normal time and took her own life.
If the woman in this case had been planning to be away from home, he could seen that as the perfect opportunity. Again, I have seen that many times.
Unfortunately, I could give countless similar examples. Those who have decided to kill themselves - will succeed.