Because Cortez's mother taught bookkeeping, she was able to ask hard questions and drive the sales people out of her house. Cortez says this kind of operation is after commissions whether or not the investment is right for the purchaser.
fleece= cheat, or swindle (人)から巻き上げる、だまし取る。{商}抜け駆け的に(暴利を)せしめる gullible retirees naive=a lack of experience gullible=a bit more of a lack of maybe suspicion.