My mom offered to update my resume for me since I don't have a computer, after having my interview, getting a contingent job offer, I'm waiting for my background and drug test to come back. I know I will pass everything but my worry is looking over everything, my mother must have misunderstood the start date I told her for my current job. I know I should have looked it over but I didn't think to because she's always good with these things. What should I do? Should I say something? Or wait and see if it comes up?
I would say it depends on the severity and importance of that erratum.
If it changed your total time in that company by a significant amount (say you worked there for 1 year but the date actually says 1.5 years) I would write an email to them explaining the misplacement along with the corrected version of your Resume. Nothing too complicated, just point out the change and politely apologize.
If the date was just some days or something not so significant not writing the email should be ok.
However, personally I would write the email no matter how minor the change was, so there is no chance for a misunderstanding or something undesired. Either way, don't forget to update your resume for future interviews.