Mangala is an empowered widow from the beginning because Akheraj let her be so by not killing her in some way. Maybe he wanted her for other pleasures and still waiting.
Mangala empowered herself for crucial moments donning devi avatar.
Beating Kundan is not due to empowerment but uncontrollable anger against him.
Her approach to most of the issues are driven by practicality than idealism.
She reacts to some issues strongly, to some issues less strongly and to some issues not at all except feeling anguish.
She had enough reasons to use violence against Harki(when Harki burned Nimboli's hands and tied Nimboli in the forest) but she looked on helplessly or with some indifference.
She had enough reasons to take on Akheraj and the most important reason is two killings, the former related to her husband. Yet she did not beat him the way she beat Kundan.
Kundan was much more brutal with Urmi but Mangala did not react thinking that its ok.
Only In nimboli's present case, she reacted.
Coming to her goals. Now she wants Nimboli should be with her and not taken away.
She will keep Akheraj and family in fear of losing elections, police so that Nimboli will be safe in that house only.