A Possibility

Cassandra Haven did not mind the wear and tear that came with age. As far as she was concerned, those were battle scars that showed that she was resilient.

What was the occasional joint ache and back pain when compared to all of the experiences that she'd had throughout the years? But even so, being older really did have its disadvantages. 

If it were up to her, Cassandra would have been searching for eternity if she had to. She never would have given up on trying to find her son and Emily.

But her body was far too old for her to push it past certain limits. And she had finally reached that limit. She wanted to deny it, to keep going. But her body's protests were too great for her to keep ignoring them.

Looking over at Jane, she realized that the other woman, even if she was staying quiet about it. Was also having the same difficulties as Cassandra.