Then, she still needs to provide her income proof and the copy of tax return plus the stock statement. Her income has to be enough to cover her entire family members and your wife (> or = 125% the 2025 poverty lines ) indepently, not include your income (your income does not count in this case). If she uses entire her family for the I-864, her spouse needs to file I-864A with her I-864.
Check this link for 2025 HHS Poverty Guidelines for Affidavit of Support:
2025 HHS Poverty Guidelines for Affidavit of Support | USCIS
