Her predecessor, Kiraitu Murungi, who had managed six consecutive electoral victories since 1992, every time on a different party platform.
Also in the race in which Mwangaza garnered 209,148 votes, against Kiraitu's 110,814, was United Democratic Alliance (UDA) candidate Mithika Linturi, who polled 183,859 votes.
Linturi, who has since been appointed Agriculture Cabinet Secretary by President William Ruto, was a third-term legislator with cunning political instincts. He was also riding on the UDA wave but still could not beat Mwangaza, who served as Meru Woman Representative for one term.
Kiraitu, who had already launched his Devolution Empowerment Party (DEP), was characteristically taking time to decide whether to align with Kenya Kwanza Alliance or Azimio where he eventually landed.
With her long history with Ruto since the No campaigns against the 2010 Constitution and United Republican Party (URP) days when she was the party's Meru branch treasurer, it was curious then why UDA was not considering Mwangaza to fly its governor race flag on August 9.
"I think Mwangaza is a lone-ranger and an abrasive politician who cannot work with anyone," Linturi had said at the time.
But despite all that success, Mwangaza is facing a tough political challenge as the relationship between her and the 69 MCAs appears to have hit rock-bottom.
She has in the past accused Linturi and Senate Deputy Speaker Kathuri Murungi of trying to influence selection of senior office holders in her government.
While Linturi has been busy as he was being vetted by MPs for the Cabinet slot and largely quiet on the matter, Kathuri has attempted to offer leadership and has twice been accused of not being impartial.
After a round of meetings with the Meru assembly leadership this week, the governor's allies dismissed the Senator of adding octane to the fire.
Sources say the elusive kamukunji between the governor and the MCAs could happen as soon as this week.
Meru residents have been treated to drama from the time both Mwangaza and MCAs took oath of office.
The governor's bid to deliver her inaugural address to the assembly was thwarted as her arrival at the assembly turned into a fiasco, after MCAs, including the 25 women in the House, walked out on her.
"So it can't be gender bias as her allies would want many to believe," said one female MCA nominated by Kiraitu's DEP.
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Her relationship with MCAs aside, discontent is brewing in some senior offices because of the place her husband, Baichu Murega, has occupied in the administration.
Murega has, just like he did during Mwangaza's campaigns for the seat, been stuck by her side. She acknowledged him on the day she was declared winner as the biggest contributor to her victory.
Mwangaza is seldom seen without her cowboy hat clad husband, whose presence at official functions is said to sometimes cause discomfort among some people.
Mwangaza's detractors argue Murega is a "distraction the administration can do without" as the governor sets her eyes on fulfilling her development pledges.
But she has stuck by her man in the face of the onslaught, insisting she would not be distracted from her work as governor.
Accusations have been levelled against her from all sides, with some MCAs claiming she has refused to involve them in important developmental processes, and the latest is a petition by a resident, Salesio Thuranira, aiming to impeach her.
Mwangaza on Friday confirmed accusations that she has her sister as her bodyguard on secondment by the Kenya Police Service and another sister as personal assistant from her earlier office as Woman Rep.
A long list of alleged relations hired by the devolved unit has been circulating online but the governor has said she has done nothing wrong and that the opposition against her is inspired by a bid by some political forces who want her out of leadership.
"There are intruders. There are people who have an eye on 2027 (governor's election). They are the ones fuelling it. They are trying sabotage," the governor said yesterday, a day after she visited the Ethics and Anti-Corruption Commission (EACC) to shed light on allegations levelled against her.
Murega has also come out fighting against those who want him to stay away from official events and offices.
He comically asked the EACC to make him understand the boundaries, demanding to be told whether he was allowed to stay in the official residence or ride in the same official car as the governor.
He said his detractors had subjected him to gender-based violence.
Yet controversy refuses to leave Mwangaza's government, which has imprints of former governor Peter Munya in several senior appointments while the only Kiraitu ally retained is County Secretary Rufus Miriti.
In the county assembly, Kiraitu's DEP is the Majority Party while Munya's ally Ayub Bundi is the Speaker. UDA is the minority party.
Political and governance expert Gitile Naituli is of the opinion there was misunderstanding by MCAs and residents about the place of Murega in the affairs of the county.
"Murega Baichu is a spouse. When he goes to a meeting he should sit down and not act bossy because he is not elected," said Prof Naituli.