[6] During her time as a city councillor, Fennell was actively involved in several committees, including those for Economic Development and Official Plan Review.

[6] This period also saw Fennell active on the Airport Tri-Municipal Committee, the Brampton Board of Trade, and the Downtown Business Improvement Area.

[10] She acted to protect Brampton's position on Peel Regional Council, including negotiating with the designated provincial facilitator, Justice George Adams.

During Fennell's tenure as mayor, Brampton became debt free and also was assigned a Triple AAA Credit Rating.

[citation needed] In 2007, Brampton was named a finalist in the World Leadership Forum, for best led city in the category of town planning.

[13] Fennell is accused of secretly and illegally lowering her own salary in 2013 to avoid, for the second consecutive year, being publicised as the highest-paid mayor in Canada; Brampton is the ninth-largest city.

[citation needed] Council colleagues attacked various budget items, including expenditures for a 'vehicle' and a 'contract driving service, for 10 years'.

[15][16] As the parties involved needed an opportunity to seek legal advice, regardless of the merit (or spuriousness) of the claims, this tactic served to defer a key debate[17] preventing council ruling on inappropriate spending in the last sitting of the Brampton council prior to the 2014 election.

[19] Fennell overturned a council decision in late 2014 that deprived her of salary and ordered that she repay taxpayers for using an expensive car service.

In 2006 she was inducted into the City of Brampton Sports Hall of Fame in the "Builder" category for her role in the creation and growth of the NWHL.