Visitor visa to aunt ?

[gita]

I would like to invite my aunt ( my mothers sister) to visit US for 3 months. we have green card and we have one kid. My aunt has big business and have 2 teeneage kids.
My question is;
1. Who should be the sponserer? Me or my Husband?
2. Who should make the affidavit and write the invitation letter?
3. My aunt is just 38 years old, how much percentage of chances are there for the visa, did anybody of this young age got the visa?
4. If the visa got rejected will it be in our records and next time when we sponsor for some other like parents or somebody, does their chances will get reduced?

Please reply ASAP.

[immihelp]

If you are working and able to sponsor her, you do that. Else let your husband do that.