Hi someone please help me:

My child is filling a separate petition for I-751 to remove conditions on permanent residence.
In part 6 "signature," is she the only one who has to sign the form (she's over 18)? And where is my spouse's signature?
And the fee still $545?

Thank you very much for your help, God bless you!

Yes.

Spouse signs her own form I-751

My child is over 18, she needs to sign in the I-751 form, where is my husband to sign? and he needs to sign too because it only has the Spouse's opation to sign.

Please help me for this,
thank you!

Your 18-year old child fills out the form, indicating that she is filing the form alone at the top. At the bottom of the form, since she is filing the form alone, she signs only where it is indicated:

I certify, under penalty of perjury of the laws of the United States of America, that this petition and the evidence submitted with it is all true and

correct. If conditional residence was based on a marriage, I further certify that the marriage was entered in accordance with the laws of the place

where the marriage took place and was not for the purpose of procuring an immigration benefit. I also authorize the release of any information from my records that the U.S. Citizenship and Immigration Services needs to determine eligibility for the benefit sought.

Signature Print Name Date (mm/dd/yyyy)