I have watched your screenshots. Her team should be good and consistent, and most teams in your league seem not to be able to compete with it. I believe your team and the 3rd place may challenge it but failed to give big surprise.
When teams promote to higher levels, the real abilities of league teams will be closer. There will be less teams with undefeated seasons.
I just checked screenshots of first 4 seasons of my Level 18 team. It also had at least 2 undefeated seasons. But these are not its best scoring seasons.