[spoiler]And If she tried to commit suicide, why didn't the Collins family get her to a doctor?[/spoiler]
That's a good question. Why didn't these people ever ask for help. Remember David trying to do away with his father (at least twice) but it's just swept under the rug. Liz almost ended up jumping off Widow's Hill a few times. However, Liz does call in help for David the time he's being terrorized by Barnabas.