First, I hate these kind of decisions it drives me nutty. I don't want to rule out good tenants due to bad data or irrelevant data nor do I want to overlook serious defects that could cause me future issues. However, having inherited a number of tenants from past acquisitions, I can tell you the tenant pool isn't so easy to sum up in data like this. I have some great tenants I inherited that I would have likely screened out. I've let in one or two stinkers despite my best screening attempts.
"bankcard account balances are too high in proportion to credit limits" could mean she has an old card with a 500 limit and it's at 500 or it could be a 100K card maxed out so it's not a great benchmark without the detailed report.
The delinquent account thing is concerning, again, look at the data and see what the root of the problem is. If it's old or a one off that may be a data glitch or some other reasonable issue (to you).
I would identify the precise entries in the credit file creating these issues and ask her to clarify what's up.