Brady, the stadium operators and the Metropolitan Police faced a two-hour grilling from the London Assembly Police and Crime Committee following the crowd trouble at the ground this season.
But while Brady admitted there have been some "teething problems" at the club's new home, she called for some "perspective" into the disorder.
Commander BJ Harrington, of the Metropolitan Police, revealed there were six arrests at the Chelsea match and 18 in total at the stadium this season - nine of whom were West Ham supporters.
Brady said: "We are coming up to the halfway point of season and there have been 18 arrests at matches. At Arsenal last season there were 60, and at Manchester United there were 57.
"At an Aston Villa match recently there were 14 arrests.
"We have had teething problems and accept that any disorder is disruptive, but we want to put some sort of perspective on it.
"We have taken strong and decisive action and we are adamant that we want to eradicate the problems.
"The majority of West Ham supporters are passionate and well behaved. We are talking about a very small minority which we have successfully identified and banned."