The only question I see is no one can claim spouse as dependent but her sister claimed her as a dependent.

[VolvoGirl]

And you should have added this on to your first question.  Otherwise it gets confusing.

[VolvoGirl · Accepted solution]

Here's a couple screen shots I made.  Will these help?

[KrisD]

Since you are filing separately, select "None of the above" on that screen. 

[edited 03.11.2019 I 3:15pm]

[ryanchambers799]

The only question I see is No one can claim spouse as their dependent for 2018

[Texas Roger]

Why did your spouse's sister claim her as a dependent? If you are filing a married filing jointly tax return for any reason other than to get a refund of taxes withheld, no one else is allowed to claim your spouse as a dependent on their tax return.  If they did, they will have to file an amended return to remove your spouse as a dependent. You will have to print and mail your return to get it accepted.

[ryanchambers799]

I’m filing Married filing Separately but it has been rejected twice.

[Texas Roger]

What is the specific reason for rejection?

[ryanchambers799]

Spouse claim as a dependent is not checked than the spouse SSN must not be the same as a dependent SSN on another return.

[KrisD]

On that screen select "None of the above"
Please see screenshot in updated answer above.