What about Ephesians 6?

Ephesians 6:1 in the King James  says—
Children, obey your parents in the Lord, for this is right.

"Children" generally means offspring, and the original Greek word, transliterated as teknon, does not limit the meaning to prepubescence.  In fact, its definition spans a wide range of meanings.  It can be an term of affectionate address such as a priest might use: my child. It can mean a male child, which would not apply to KatieLyn! The Greek word was also used for a pupil in a teacher/student relationship. And Larry Pierce, editor of The Outline of Biblical Usage, lists some additional usage: (a) children of God: in the OT of "the people of Israel" as especially dear to God, in the NT, in Paul's writings, all who are led by the Spirit of God and thus closely related to God; (b) the votaries of wisdom, those souls who have, as it were, been nurtured and moulded by wisdom; and (c) cursed children, exposed to a curse and doomed to God's wrath or penalty.  All-in-all, the term is pretty inclusive, and we cannot rule out its being applied to KatieLyn just because she is turning 30 soon.

Let's consider other translations, both literal and contemporary:
⁜ Children, obey your parents as the Lord wants, because this is just and the right thing to do.
⁜ Children, obey your parents in the Lord [as His representatives], for this is just and right.
⁜ The children! obey your parents in the Lord, for this is righteous. 

The obedience that is right is the obedience "in the Lord."  To say it another way, the grammatical structure pairs "in the Lord" with obey, not with parents. The point made here is that nowhere is there a demand for blind obedience of parents. The command is: Obey in the Lord.  The phrase "in the Lord" acts to put limitations on obedience. A demand for actions which are not loving and in the will of God do not have to be obeyed; they should not be obeyed because they are neither just nor right. 

The child should obey as a WWJD* kind of thing.  Obviously Jesus could not have obeyed a command to sin. Peter offers some clarity in Acts 5:29 when he states, "We ought to obey God rather than men."


The Instruction Continues...
Ephesians 6:4 in the King James says—
And, ye fathers, provoke not your children to wrath: but bring them up in the nurture and admonition of the Lord.

Let's consider other updated translations here too:
⁜ Fathers, do not exasperate your children; instead, bring them up in the training and instruction of the Lord.
⁜ Fathers, [or Parents,] do not make your children angry, but raise them with the training and the teaching of the Lord. 

The sorry fact is,  KatieLyn's parents were wildly disobedient on this one. Her mom was chronically rekindling the fire and inciting arguments. In hindsight, it became evident that KatieLyn told Joe a glossed-over version to protect her mother's reputation. This allowed Joe to be deceived into thinking KatieLyn was handling it okay. She was not.  

KatieLyn's dad did nothing to intervene; and that makes him an accessory to the fighting.  KatieLyn's dad did the ostrich thing and stuck his head in the ground while his wife was systematically destroying his daughter's first love. Meanwhile, KatieLyn was doing the Pollyanna thing with Joe, pretending that her relationship with her mom was great, even as her mother was ripping her world to shreds. 

But the problems went even further than Gwen deliberately exasperating her daughter into a loss of faith. Huge deficits in the nurture/training and the admonition/teaching are evident as well.

Even though KatieLyn gave very little reason for her parents to mistrust her, they did. Her mother especially doubted KatieLyn's judgment at choosing a husband. ...

Let me digress a bit and tell my story about a friend who was studying at seminary. He studied the coursework and got good grades; all his classes were complete and had earned an outstanding GPA.* But he never graduated. The certificate he received, in lieu of a diploma, said ABT. He never got a job as a pastor. I lost track of him after he became a jeweler at a Kmart, and that store is no more.  There is a parallel here, even if it is a bit oblique, with the way that Gwen has run KatieLyn's life: She put in the love, time, and effort to raise a great daughter, but then she never let her efforts come to fruition. She stubbornly stopped short of the finish line because she herself was not sure about wanting to pursue the final step. It is like she aborted the nearly full-term dreams daughter because it was uncomfortable for her, just as my friend aborted his dream of going into the ministry when he discovered an easier way to make more money.  They were walking by sight and not by faith.

 
Bottom line though, Gwen did not trust her own daughter to hear from the Lord. Even though Gwen had over 28 years to invest and teach her child to follow the godly leading of her heart, Gwen did not trust that her teaching had been effective, she did not trust the Lord to work things out, and she did not trust her daughter to make an adult decision on her own. And THAT is a colossal failure in parenting!   

The Lesson
KatieLyn tried to follow the command to obey her parents. She was so OCD about it that she gave up her first love, totally confused by her parents' misleading, and ultimately ungodly, "guidance." Meanwhile, her parents were in flagrant disobedience to the command to not stir up anger in your children. I'm sure Gwen has come up with some rationalization for it that she can live with, even though her "advice" and seizure of control over communication has been harsh to the point of cruelty and abuse. As hateful as it was toward Joe, the damage to her daughter's self-image is probably even worse.

The sixth chapter of Ephesians continues with two more themes: 
• One is about the armor of warfare where we are reminded that "we do not wrestle against flesh and blood, but against the rulers, against the authorities, against the cosmic powers over this present darkness, against the spiritual forces of evil in the heavenly places." Gwen is not the real enemy, but she has allowed the enemy to use her to destroy her daughter. That is tragic.
• The other main theme is the call to pray continually. There has never been a day since KatieLyn ran off into the middle of the night that she has not been brought before the Lord. This situation is far from resolved. 

If KatieLyn tries to "just move on" without addressing the root of the problems, then she will not have pleased God. I know this because without faith it is impossible to please Him, for he who comes to God must believe that He is and that He is a rewarder of those who seek Him, (Hebrews 11:6). This is very different than seeking approval from one's mother    




* Key to abbreviations
WWJD What Would Jesus Do? 
GPA - Grade Point Average
ABT - All But Thesis
OCD - Obsessive Compulsive Disabled