If intercepted, she'll be apprehended and placed in removal proceedings in immigration court. She'll probably remain in detention unless can be freed on bond.
Best to submit an I130 petition on her behalf right now, as an insurance policy (that will stop or delay her removal until you actually acquire citizenship and can upgrade her petition).
Behar Intl. Counsel 619.234.5962 Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.
what will happen as she is illegal right now?
She is deportable and it is up to the government to decide whether to try to deport her.
would she be required to leave during the process?
Depends on whether she can prove a legal entry to the US and whether you are a US citizen.
You should retain an experienced immigration lawyer to review all the facts, advise you, and handle the case. You can find one through http://www.ailalawyer.com.
J Charles Ferrari Eng & Nishimura 213.622.2255 The statement above is general in nature and does not constitute legal advice, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship. Answers on Avvo can only be general ones, as specific answers would require knowledge of all the facts. As such, they may or may not apply to the question.
She is F2 category spouse of LPR. The wait will be few years. If file as an LPR she will be upgraded into immediate relative category when you become US citizen. If she can prove legal entry into the country she may not have to leave to adjust status to LPR. If she had 212(e) restriction while in her student status she may need to file certain waiver. Best if you consult with your own attorney before do anything. Good luck and congrats on your baby!