Assuming you are a U.S. Citizen, you can file for her green-card as an immediate relative YES. You can still file even if you are a green-card holder, but there are wait-times. She will get a GREEN-CARD not U.S. Citizenship. Consult with a experienced immigration lawyer to help you out.
You said you made $24,000 so you meet the poverty guidelines. You must still be working and making that same amount or more currently by providing your recent pay-stubs. The amount for 2 people is $19,387 given you have no dependents on your U.S. tax returns.
You can file an I-130 petition, But this petition in of it self does not give you a visa or green-card. You may not be eligible for the green-card in the United States because you entered without inspection. Its important to speak to an immigration lawyer.
A few DUI's? two, three, four?? He should hire a experienced immigration lawyer immediately and request a bond hearing with the Court. Of course the immigration lawyer needs to know all his criminal history. EVERYTHING!!
No, brother under 18 will not be included in the parents petition. You may want to file a humanitarian parole for the brother basing it on the parents intent to immigrate to the United States and cannot leave this child behind. Speak to a experienced immigration lawyer to help you. Humanitarian parole is discretionary and you must make submit a good and compelling case.