Becareful with taking chances, some lawyers might be just trying to retain you to make few bucks (however your wife's case does not have any good chance of getting through). Officers are not allowed to adjudicate the cases like hers who has overstayed the visa . I know freind of mine who had overstayed one day before he submitted 485 application , had his GC denied recently by Immigration adjudicators. well just be aware before you spend money on something which can not be done. however you may just start your process as soon as possible that way you can have yours and wait for her to file it later.