Deductions & credits

Thanks.  We have 2 dependents. I have suggested we both file as HOH since we have been living separate for over 6 months of the year and share 50:50 custody so can each claim a child as a dependent. She disagrees and says only 1 of us can claim HOH and it should be her.  I am the higher wage earner and thus the custodial parent in a 50:50 situation.  Since we are considered separated for income purposes once I filed for divorce on Jan 31, I only need to consider 1 month for community income in California. It's not clear how to put this on form 8938 when I don't have her full year of income but I can guess.  We also have a jointly owned rental but she won't share all of the expenses with me unless I agree to file jointly and while I can guess I would prefer to have to actual expenses to put on my separate return