"She was likeable but immature, selfish, shallow, and ditzy. As she got older she became more career ambitious, but still dated the worst guys until Andy was introduced.
The character development she had from that point was so good. She valued herself more and realised she deserved respect from men. She matured and became thoughtful, deeper, and less of a ditz. Andy was her total opposite who helped her grow into the best version of herself, and she also helped him.
Then he left and so did her character development. As soon as she got back together with Dylan, she lost ambition and regressed into her high school self. She deserved so much better than just getting pregnant and having a quickie wedding. If it was really a 'modern' family, she should have been single and focused on her career as the stronger person she had become."