Joey King's character leaving out of the blue

What was up with that? in the last episode she was in she was having a sweet heart to heart with Coleen and was asking her if she and Matt would be in the delivery room with her, and it ended with them hugging and seemingly on the same page.

Then a episode or so later Matt and Coleen just randomly bring up that they haven't heard from her in a while since she went to her parents, and we find out shes decided to keep the baby and thats that.

They had like 2 or 3 episodes with her character, and the last one with her ended happy and like we was gonna see her again, but then she just randomly leaves and we don't see her again and that happy moment we last had with her was just bullshit i guess. Was it something with her not being able to do the show anymore due to filming something else? cause it seems like they really intended to have her character in at least in one more episode.