You should not "Hijack" someone elses thread, please post separate threads in future. This thread is started by the first poster and posting etiquette requires you to limit your posting relevant to the original post. If you want to raise another issue, please post in a new thread.
Having said that, your place of interview depends on the address you provided on your I-485 application. Did you also file I-131 for advance parole? If you did, you should receive a parole document which allows you to travel out of US and return without affecting processing of your application. Without a parole document, your application will be deemed abandoned when you leave US.
Interview usually take 1-4 months after fingerprinting, depending on the workload the USCIS center processing your application.
Did you check status of your application online at USCIS website? Did you or your daughter receive any Request for further Evidence (RFE)? Did you also submit a) sealed medical reports, b) proofs of birth and marriage for you and your husband and c) your daughter's birth certificate showing that you are indeed her parents?