Just for my own curiosity, how guilty is your new client?  Did he come up with the plan to add dependents and then got cold feet once he found out people go to prison for tax fraud or did the ace tax preparer come up with the plan and he just went along for the ride?  In either case, I wouldn't touch the return or the client with a ten foot pole but I would love to see the "tax preparer" rot in a jail cell if this is the standard operating procedure of her "tax practice".