Lots of ideas here, but don't exclude the possibility she may simply be the sort of person who has more time for people who are the most useful to her at the time. That won't necessarily be the fault of her upbringing - kids are born with embryonic personality traits of their own. Not sure if you said her age somewhere in this thread, but my daughter grew out of her youthful selfishness, and started thinking about other people's emotional needs, while my son didn't (both now in their 40s). So it may simply be a matter of time. Does she pick up the phone to you and answer when you text? If so, there is hope 
Desperately sad story of the assisted suicide of a grieving mother


