You have to start by changing the bad habits your client is using. It is fine to use collected cash for expenses BUT, they should be paid from bank-type Petty Cash or Cash on Hand- meaning instead of the daily cash sales going who knows where they need to be deposited to Cash on Hand. The twice a week real deposit then is recorded as money movement from Cash on Hand to Checking.
The alternative is posting each daily cash sales to Undeposited Funds, then twice per week depositing these less cash back to Cash on Hand from which Expenses have been or will be paid. This way you run CoH in the negative before deposits and nothing wrong with that just the client will freak when she sees account balances below zero
