My child's mother did not file a 2018 or 2019 tax return. She was supposed to claim our child and didn't file because she had no income. How can we file with no income?

[DavidS127]

A "zero income" tax return must be printed and mailed, it cannot be e-filed.  But, unless you are due a refund for taxes withheld, filing a tax return without earned income will not result in a refund.  And, in most cases, you aren't required to file a tax refund if you don't have income.  See the Publication 501 Table 3 at this link for situations that require a tax return even when you ....

If you are concerned about a stimulus payment when you or your child's mother did not file a tax return,  click this link for the TurboTax Stimulus Registration product.  Stimulus Registration can help people not required to file a tax return to submit all the necessary information to the IRS so they can quickly and easily get their money.  

[Hal_Al]

Who is "we"? What is your living situation? Are you married to the mother?  What are you trying to accomplish?

If he mother didn't claim the child, then the father probably should. 

If you and the other parent live together, either one of you (but not both) may claim the child. You may decide between you which one will claim the child. Only if you can’t agree, do the IRS tie breaker rules apply, to see who has first choice. If It may be worthwhile to prepare trial returns, both ways,  to see which way the family comes out best. This tool may be useful: https://turbotax.intuit.com/tax-tools/calculators/taxcaster/?s=1.