In her 'later' years..my mother cried quite a-bit. I noticed when I called, or would stop by, etc. I asked her why several times...
Finally got an answer, she was "down"...or more often said she had the "blues" . I asked why?...Finally got an answer...
In a nutshell...her friends were mostly dead, the few who weren't were her age, as such , did nothing. She felt like doing nothing, the docs kept telling her, don't eat this, don't drink that, all she did was go to the doc. My sister [@ that time] lived in another state. I should spend more time with her....I spent plenty of time with her...it was never enough. I told her once that I cannot become her new "social" life / circle....etc,etc.
  Sound familiar ?
 I think for some folks, crying is a relief valve? I think depression of that sort is a far cry [no pun intended] from real clinical depression. Might sound cruel?...but I do not think it's serious ?
None of us like aging & what it does to us, in any aspect...IMO a good cry, or maybe a stiff drink are coping tools? Maybe even healthy?
We cannot turn back the clock, for ourselves or anyone. And we [in reality] can do little about the ravages [of] aging. Again opinion but i say deal with it how ever we can, in what ever reasonable way works for us.
Perhaps that is what your friend is doing ?