Married Filling Jointly | ITIN Applied | IN and IL State

Dear Community Members,

This is first year I am filling jointly. I have applied for ITIN for my spouse. I have got our federal return mailed with form W7. However, I have not filled my taxes for IN and IL (I have to do both the states as part year.) yet. This year, I owe money to IN and IL both. My questions:

1. Can I file my IN and IL returns without my spouse's ITIN? I will mention applied for in the form.
2. The agent who helped us with W7 form said that states will not accept the returns with applied for status of my spouses's ITIN. She suggested to pays the taxes I owe to both the states and apply for return extension with them. Then when I get the ITIN for my spouse, I should file the return with the states.
3. If your suggestion is to go with the extension option, then please point me to the procedure for paying the taxes I will owe and the process for applying for the extension.

Please feel free to ask for clarifications.

Thanks