Poor girl....

From the AP:

Ashlyn is among a tiny number of people in the world known to have congenital insensitivity to pain with anhidrosis, or CIPA — a rare genetic disorder that makes her unable to feel pain.

Generically speaking, pain is what keeps us from accidentally killing ourselves. Losing the ability to feel pain sucks ass, to put it mildly. I would guess that she'll end up living a very inconvenient life. She'll have to spend a large part of each day checking herself over for injuries, will have to carefully design her life around injury-avoidance, and similar such things.

As the article mentions, developments like appendicitis could easily be a death sentence for her. While easy to treat, your survival prospects depend heavily on a timely diagnosis. Without pain to tip you off, the chances of timeliness dwindle.