My wife applied for adjustment of status with the following forms:I-864,I-864A .I am the sponsor on 864,and my dad is my household sponsor since I am unemployed.
Someone advised us that my wife can apply for baby food-stamps. I know we can do that,but will it hurt us in the long run,since I am the sponsor and my dad is my household sponsor?
Thanks,

You are probably meaning WIC. Since you are with her you would probably have to include your income. The dad may not have to if he is considered the one you are 'renting' off. Since you live with her and your income would be counted, they would not make her go after child support that they normally would if you were separated. It all depends on all the income they would take into consideration to come up with the eligible amount or if she would even qualify. I am not sure if it would hurt in the long run. Probably balance out if anything

Did the child adjust status too? If not, then there is no problem with the child applying for anything.

Your wife can apply for food stamps if she qualifies, of course. But after she becomes a permanent resident, the government could sue the sponsor(s) for any benefits she got after she became a permanent resident.