1) NO...if she filed a MFJ tax return, you do not file form your own account....the one she did is enough.
2) Have her print out the forms and LOOK at them. You should always print a paper copy to look at, and save in your own home tax file. Online "free" software will not allow you access to past year's tax returns, so print them out every year.
3) Re-Check the filing status for the tax that was filed here. The SSN for the first person listed on that tax return must be used...so you do need to see it first.