Teenage daughters with different mothers fight during family therapy, causing father to become upset with the oldest when she says she’ll never be close with her half sister

Welcome back ladies and gentlemen of the internet. When mixing families, things get complicated. Growing up in the same household as stepsiblings, or halfsiblings is hard for nearly every child. The adjustment period could last for years, putting the parents in tough positions. It must be torture knowing your kid is in so much pain and that you're the cause. Not that anyone should feel guilt or shame for needing to make the difficult decision of divorce. It's only natural that it would affect someone on a deep level, and the recovery for everyone involved can take a long time. Therapy is a helpful way to build skillsets for handling tough times. 

In this story, the protagonist is a young teenager or 16-years-old. She has a half sister who's 13-years-old, and their relationship is on the rocks for obvious reasons. They're both having a hard time dealing with their situation, living together, and trying to deal with a mixed family dynamic. The father tries to get everyone to attend therapy together to mend their difficulties and pain, but in vain. What would you do in this situation? Read the full story below for all the juicy details.