I can't understand why Harris hasn't been focusing on the economy all along - but then… rich folks, never missed a meal…
Rather than rushing to say "me too" when Trump says he'll make tips tax-free, she should (sez I in my humble simplicity) have said "We'll make the humiliating necessity of grovelling for tips a thing of the past - we'll make waiting on tables properly paid so no one has need of tips".
And if she has a real focus on the economy, she could talk about the cost of running a car - and paying the enormous proportion of your wages that this costs. (That US government link shows the average cost per 15,000 miles as around $12,500.)
She could talk about how much Americans pay for health care (again, nearly $12,000 per year on average). She could talk about how badly Americans are served by this, with average life expectancy dropping in the US - a lot of this recent dramatic drop to be blamed on the Trump administration's disastrous response to the Covid pandemic and the drugs crisis.
She could talk about rising food prices - and how this is hitting poorer people disproportionally, because processed foods are rising in price far faster than good food cooked from scratch at home (cooking-from-scratch is easier for people who don't have to hold down two or three jobs to keep their household).
She could talk about wages for new jobs declining, and how the American culture of secrecy about salaries is partly to blame for this - in most countries, your salary is not a secret, and this makes it easier to see when you need a raise or a different job.
Just a start…