"自分" is often used instead. It is natural for a woman who has lost her husband to worry about her future, but in the Japanese way of thinking, it is considered indecent to talk openly about these personal anxieties, so you should use modest expressions in this situation. In this case...
@YUKINANN I think I have heard this だろう on japanese movies before. it is like when the say something and want to somehow impose agreement on the other person. Sometimes they even say it very loudly だろう!!??@