If i filed head of household last year with my wife will her 2019 agi be the same as mine

"Head of household" is a special filing status for single parents, it is not the same as being "head of the house" in a social sense.  If you are married, you can't use Head of Household unless you were separated from your spouse for at least the last 6 months of the year (from July 1 onward).

If you are married and living together you should generally file as "married filing jointly", even if only one spouse works.  If you filed jointly last year, your spouse has the same AGI as you.

If you really did file head of household, then your wife filed no tax return and has no AGI (unless she filed a separate return as married filing separately).  You can try zero to get a joint tax return accepted this year.  You would also have to file an amended 2019 tax return to change from head of household to married filing jointly, unless you really were separated for 2019.