Why would my wife need my agi if we are filing separately? It keeps rejecting her and wanting my agi. I have filed already and did not have to put in her agi?

It could happen if you living in a community property state. You need to enter your spouse's AGI to file your tax return, even if you file separately. It does happen, you might be able to file without the information, however according to the IRS rule, it could be a reason for rejection. 

Well we are in the process of a divorce or beginning stages of it so I didn't really wanna give her my agi if she didn't really need it. Wanted to make sure she wasn't telling me a lie just to get info.

Also, if you filed a joint return in 2019, You'll both use the same adjusted gross income (AGI) from your originally filed 2019 joint return.  To prevent a rejection, don't split or allocate the AGI, even if doing so seems more logical to you.