Marget had never thought that Tiana would come to her house and make such a huge fuss. However, the truth was that Marget wasn't the one who kidnapped Tiana's child. Nonetheless, when Tiana barged into the house and started questioning her, she suddenly had an idea.
At that time, Tiana was furious and was convinced that Marget was the one who kidnapped Eric. All Marget needed to do was provoke Tiana so she would do something irrational and unacceptable.
Then Marget would be able to force Austin to make a choice and get rid of Tiana once and for all.
That was why Marget didn't even care to run away; instead, she even hit Tiana. Due to that, Tiana almost strangled Marget to death in a fit of anger.
Since they had such a huge fight, needless to say, Marget would definitely not give in.
However, all Austin did was to demand Tiana to apologize. His protective action towards Tiana infuriated Marget.